Problem in Subtraction

**rhodarose** · 12-13-2010, 03:54 AM

this codes:

HTML Code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<script type= "text/javascript"> 
function startCalc(){
  interval = setInterval("calc()",1);
    }
function calc(){
    var qty = new Array(2);
    qty[0] = parseFloat(document.myform.inqty.value);
  qty[1] = parseFloat(document.myform.outqty.value);
  
myqtyval = qty[0]-qty[1];
document.myform.myqty.value = myqtyval;    
}
 
function stopCalc(){
  clearInterval(interval);
}
</script>
</head>
<body>
<form name='myform' action='test.php' method='post'>
Input<input type='text' name='inqty'  onFocus='startCalc();' onBlur='stopCalc();' />
Output<input type='text' name='outqty'  onFocus='startCalc();' onBlur='stopCalc();' /><br/>
myqty<input type='text' name='myqty' value=''  />
<input type='submit' name='submit' value='save' />
 
 
</form>
</body>
</html>

has the concept of what i want that after i insert number in output the result was automatically appear in qty but the problem in this code it did not use on key enter and I don't know how can i put that code n my php file where I attach.

I'm sorry, i do understand the concept but I don't know how can I code it and where i can put the codes.

Thank you..

**Nile** · 12-14-2010, 01:47 AM

I don't know what to tell you - my script works fine in IE 8, IE 7, and FF with no errors for me.

**jscheuer1** · 12-14-2010, 04:25 AM

Originally Posted by rhodarose

I used this code:

<script type="text/javascript">
var c = document.getElementById('inqty');
var b = document.getElementById('outqty');
var a = document.getElementById('varqty');
//define c, b, a

var performSubtract = function(e) {
var key = e ? e.which : window.event.keyCode; //get the key, 13 = ENTER
if(key == 13){
a.value = c.value - b.value; //subtract and set
}
};

c.onkeydown = b.onkeydown = performSubtract;
</script>

Line: 38
Error: 'c' is null or not an object

You're not showing any element with an id of inqty. So probably it either hasn't been parsed yet by the browser at the point at which the code defines it:

Code:

var c = document.getElementById('inqty');

Or it doesn't exist. This could be due to page organization that's inadequate to this task and/or a typo and/or something else. But it could possibly be something else entirely. If you want more help on that error, to tell what's what -

We need you to put up a demo page that shows the error.

Otherwise we can only guess.

**rhodarose** · 12-14-2010, 07:03 AM

Originally Posted by jscheuer1

You're not showing any element with an id of inqty. So probably it either hasn't been parsed yet by the browser at the point at which the code defines it:

Code:

var c = document.getElementById('inqty');

Or it doesn't exist. This could be due to page organization that's inadequate to this task and/or a typo and/or something else. But it could possibly be something else entirely. If you want more help on that error, to tell what's what -

We need you to put up a demo page that shows the error.

Otherwise we can only guess.

I put tthis code:

HTML Code:

<script type="text/javascript">
var c = document.getElementById('inqty');
var b = document.getElementById('outqty');
var a = document.getElementById('varqty');
//define c, b, a

var performSubtract = function(e) {
    var key = e ? e.which : window.event.keyCode; //get the key, 13 = ENTER
    if(key == 13){
        a.value = c.value - b.value; //subtract and set
    }
};

c.onkeydown = b.onkeydown = performSubtract;
</script>

in my php codes but it did not work but no errors.

I attached my php codes.

Thank you

**jscheuer1** · 12-14-2010, 07:31 AM

Move the highlighted:

Code:

       . . . else
            {
            return true;
            }
        }
    </script>
    
    <script type="text/javascript">
var c = document.getElementById('inqty');
var b = document.getElementById('outqty');
var a = document.getElementById('varqty');
//define c, b, a

var performSubtract = function(e) {
    var key = e ? e.which : window.event.keyCode; //get the key, 13 = ENTER
    if(key == 13){
        a.value = c.value - b.value; //subtract and set
    }
};

c.onkeydown = b.onkeydown = performSubtract;
</script>
</head>
<body onLoad="document.clttype.clt_no.focus();">
<!--<p><a href="clt_definition.php">Clt Types</a>&nbsp;&nbsp;&nbsp;<a href="clt_query.php">Query</a></p>-->
<?php . . .

to:

Code:

 . . . ut size='6' type='text' name='shift[]' id='shift" . $ctr . "' onkeypress='return handleEnter(event,\"saveform\");' /></td>";
            echo "\n\t</tr>";
            }
            echo "</table>";
        } 
    echo "<p><input type='submit' value='  Save  ' id='saveform' /></p>";
    echo "<input type='hidden' name='clt_typeno' value='" . $_POST["clt_typeno"] . "' />";
?>
</form>
    <script type="text/javascript">
var c = document.getElementById('inqty');
var b = document.getElementById('outqty');
var a = document.getElementById('varqty');
//define c, b, a

var performSubtract = function(e) {
    var key = e ? e.which : window.event.keyCode; //get the key, 13 = ENTER
    if(key == 13){
        a.value = c.value - b.value; //subtract and set
    }
};

c.onkeydown = b.onkeydown = performSubtract;
</script>
</body>
</html>

If that doesn't fix it -

We need a link to the page, or any page that shows the error.

The only substitute that might work would be:

Load up the page that's giving you this error in the browser.
Use the browser's 'view source' to see the source code being served.
Select all and copy.
Paste that into a text file, save and attach that text file to a post here.

**rhodarose** · 12-14-2010, 08:13 AM

Originally Posted by jscheuer1

Move the highlighted:

Code:

       . . . else
            {
            return true;
            }
        }
    </script>
    
    <script type="text/javascript">
var c = document.getElementById('inqty');
var b = document.getElementById('outqty');
var a = document.getElementById('varqty');
//define c, b, a

var performSubtract = function(e) {
    var key = e ? e.which : window.event.keyCode; //get the key, 13 = ENTER
    if(key == 13){
        a.value = c.value - b.value; //subtract and set
    }
};

c.onkeydown = b.onkeydown = performSubtract;
</script>
</head>
<body onLoad="document.clttype.clt_no.focus();">
<!--<p><a href="clt_definition.php">Clt Types</a>&nbsp;&nbsp;&nbsp;<a href="clt_query.php">Query</a></p>-->
<?php . . .

to:

Code:

 . . . ut size='6' type='text' name='shift[]' id='shift" . $ctr . "' onkeypress='return handleEnter(event,\"saveform\");' /></td>";
            echo "\n\t</tr>";
            }
            echo "</table>";
        } 
    echo "<p><input type='submit' value='  Save  ' id='saveform' /></p>";
    echo "<input type='hidden' name='clt_typeno' value='" . $_POST["clt_typeno"] . "' />";
?>
</form>
    <script type="text/javascript">
var c = document.getElementById('inqty');
var b = document.getElementById('outqty');
var a = document.getElementById('varqty');
//define c, b, a

var performSubtract = function(e) {
    var key = e ? e.which : window.event.keyCode; //get the key, 13 = ENTER
    if(key == 13){
        a.value = c.value - b.value; //subtract and set
    }
};

c.onkeydown = b.onkeydown = performSubtract;
</script>
</body>
</html>

If that doesn't fix it -

We need a link to the page, or any page that shows the error.

The only substitute that might work would be:

Load up the page that's giving you this error in the browser.
Use the browser's 'view source' to see the source code being served.
Select all and copy.
Paste that into a text file, save and attach that text file to a post here.

i try what you said, but still it did not work, when i try to insert number in input and i press enter key and i insert number in ouput textfield and theres no output appear in varqty even I press enter key.

**jscheuer1** · 12-14-2010, 04:11 PM

The script in question:

Code:

    <script type="text/javascript">
var c = document.getElementById('inqty');
var b = document.getElementById('outqty');
var a = document.getElementById('varqty');
//define c, b, a

var performSubtract = function(e) {
    var key = e ? e.which : window.event.keyCode; //get the key, 13 = ENTER
    if(key == 13){
        a.value = c.value - b.value; //subtract and set
    }
};

c.onkeydown = b.onkeydown = performSubtract;
</script>

Isn't on the page in the zip attached to your post, and neither is any element with an id of "inqty". You do have id='inqty0' through id='inqty30' though.

I'd get rid of:

Code:

    <script language="javascript">
    function handleEnter(e, nextfield)
        {
        var characterCode = (e && e.which)? e.which: e.keyCode;
        if(characterCode == 13)
            {
            document.getElementById(nextfield).focus();
            return false;
            } 
        else
            {
            return true;
            }
        }
    </script>

and the highlighted:

Code:

<body onLoad="document.clttype.clt_no.focus();">

and this (again highlighted) and all similar (there are tons of these, but probably not too many in the PHP file that created the file you sent):

Code:

<input type='text' name='ac2l' id='ac2l' onkeypress='return handleEnter(event,"b3");' />

Add this script to the head:

Code:

<script type="text/javascript">
document.onkeypress = function(e){
	e = e || event; e.returnValue = true;
	var t = e.target || e.srcElement, re = /^(inqty|outqty)(\d+)$/, f = arguments.callee, m, i;
	function next(){
		if(!f.els && (m = t.form) === document.forms.clttype){
			var ipts = m.getElementsByTagName('input'), els = []; i = ipts.length - 1;
			for (i; i > -1; --i){
				if(ipts[i].type && ipts[i].type.toLowerCase() === 'text'){
					els.push(ipts[i]);
				}
			}
			f.els = els;
		}
		if(f.els){
			i = f.els.length - 1;
			for (i; i > -1; --i){
				if(f.els[i] === t && (m = f.els[i - 1])){
					m.focus();
				}
			}
		}
	}
	if((m = re.exec(t.id)) && e.keyCode === 13){
		e.returnValue = false;
		t.form.elements['varqty' + m[2]].value = t.form.elements['inqty' + m[2]].value - t.form.elements['outqty' + m[2]].value;
	} else if (t.type && e.keyCode === 13 && t.type.toLowerCase() !== 'submit') {
		e.returnValue = false;
	}
	if(!e.returnValue){
		next();
		if(e.preventDefault){e.preventDefault();}
	}
	return e.returnValue;
}
</script>

This will supply the functionality of both the removed script and the one Nile and you were trying to get to work. It automatically determines which field is next, and (in the case of subtraction) which fields to deal with. It doesn't matter how many or how few fields there are, as long as (again, only for subtraction) there are the three fields inqty#, outqty#, and varqty# for each number, 0 through however many. The body onLoad code pointed to a non-existent element, so was doing nothing other than throw an error. I'm thinking that you might want the subtraction activated differently though, other than just on hitting the ENTER key, and I wonder if subtraction is what's really required. But I leave both of those up to you to decide. Let me know if you need different or additional on that and want help implementing it.

**rhodarose** · 12-15-2010, 12:10 AM

Originally Posted by jscheuer1

The script in question:

Code:

    <script type="text/javascript">
var c = document.getElementById('inqty');
var b = document.getElementById('outqty');
var a = document.getElementById('varqty');
//define c, b, a

var performSubtract = function(e) {
    var key = e ? e.which : window.event.keyCode; //get the key, 13 = ENTER
    if(key == 13){
        a.value = c.value - b.value; //subtract and set
    }
};

c.onkeydown = b.onkeydown = performSubtract;
</script>

Isn't on the page in the zip attached to your post, and neither is any element with an id of "inqty". You do have id='inqty0' through id='inqty30' though.

I'd get rid of:

Code:

    <script language="javascript">
    function handleEnter(e, nextfield)
        {
        var characterCode = (e && e.which)? e.which: e.keyCode;
        if(characterCode == 13)
            {
            document.getElementById(nextfield).focus();
            return false;
            } 
        else
            {
            return true;
            }
        }
    </script>

and the highlighted:

Code:

<body onLoad="document.clttype.clt_no.focus();">

and this (again highlighted) and all similar (there are tons of these, but probably not too many in the PHP file that created the file you sent):

Code:

<input type='text' name='ac2l' id='ac2l' onkeypress='return handleEnter(event,"b3");' />

Add this script to the head:

Code:

<script type="text/javascript">
document.onkeypress = function(e){
	e = e || event; e.returnValue = true;
	var t = e.target || e.srcElement, re = /^(inqty|outqty)(\d+)$/, f = arguments.callee, m, i;
	function next(){
		if(!f.els && (m = t.form) === document.forms.clttype){
			var ipts = m.getElementsByTagName('input'), els = []; i = ipts.length - 1;
			for (i; i > -1; --i){
				if(ipts[i].type && ipts[i].type.toLowerCase() === 'text'){
					els.push(ipts[i]);
				}
			}
			f.els = els;
		}
		if(f.els){
			i = f.els.length - 1;
			for (i; i > -1; --i){
				if(f.els[i] === t && (m = f.els[i - 1])){
					m.focus();
				}
			}
		}
	}
	if((m = re.exec(t.id)) && e.keyCode === 13){
		e.returnValue = false;
		t.form.elements['varqty' + m[2]].value = t.form.elements['inqty' + m[2]].value - t.form.elements['outqty' + m[2]].value;
	} else if (t.type && e.keyCode === 13 && t.type.toLowerCase() !== 'submit') {
		e.returnValue = false;
	}
	if(!e.returnValue){
		next();
		if(e.preventDefault){e.preventDefault();}
	}
	return e.returnValue;
}
</script>

This will supply the functionality of both the removed script and the one Nile and you were trying to get to work. It automatically determines which field is next, and (in the case of subtraction) which fields to deal with. It doesn't matter how many or how few fields there are, as long as (again, only for subtraction) there are the three fields inqty#, outqty#, and varqty# for each number, 0 through however many. The body onLoad code pointed to a non-existent element, so was doing nothing other than throw an error. I'm thinking that you might want the subtraction activated differently though, other than just on hitting the ENTER key, and I wonder if subtraction is what's really required. But I leave both of those up to you to decide. Let me know if you need different or additional on that and want help implementing it.

You mean that if I used the code that you suggested I will removed those codes:

Code:

<script language="javascript">
    function handleEnter(e, nextfield)
        {
        var characterCode = (e && e.which)? e.which: e.keyCode;
        if(characterCode == 13)
            {
            document.getElementById(nextfield).focus();
            return false;
            } 
        else
            {
            return true;
            }
        }
    </script>
onLoad="document.clttype.clt_no.focus();"
onkeypress='return handleEnter(event,"b3");'

Thank you