Problem with setfocus()

[forum_amnesiac]

I have a form in which I validate that the date is input in a set format, that the date is not before today and that it is a Monday.

All of the validation works perfectly.

If the value fails to pass any one of these validation tests I want to give an alert and return to the date field for re-input, I use a small function for this.

The problem I have is that although the alert is given, the focus does not return to the correct field, it goes to the next field in the form sequence. I use "tabindex" to ensure that the fields are initially presented in the sequence I want.

Here is my JS

function fieldFocus3(msg) {
alert(msg);
document.jaugeage.startDate.select();
document.jaugeage.startDate.focus();
return false;
}

function mondaycheck(datechosen, fridaydate) {
	var dtCh= "/";
	var pos1=datechosen.indexOf(dtCh);
	var pos2=datechosen.indexOf(dtCh,pos1+1);
		if (pos1==-1 || pos2==-1){
		fieldFocus3("Veuillez écrire la date de début comme ceci jj/mm/aaaa");
		jaugeage.startDate.value = "jj/mm/aaaa";
		}
		if (pos1!=-1 && pos2!=-1){
			var parts = datechosen.split('/');
			var passdate = new Date(parseFloat(parts[2]),(parseFloat(parts[1])-1),parseFloat(parts[0]),23,59,59,999);
			var thisDay=passdate.getDay();
			Testtoday = new Date();
				if(passdate < Testtoday) {
				fieldFocus3("La date ne peut pas être plus tôt qu'aujourd'hui");
				jaugeage.startDate.value = "jj/mm/aaaa";
				}
		else {
			var myDays= ["Dimanche","Lundi","Mardi","Mercredi","Jeudi","Vendredi","Samedi","Dimanche"];
			var daychosen = myDays[thisDay];
				if (daychosen != "Lundi") {
				fieldFocus3("Lundi seul");
				jaugeage.startDate.value = "jj/mm/aaaa";
				}
		else {
			var mondate = new Date(passdate.valueOf());
			var mody = mondate.getDate();
			var monmo = mondate.getMonth()+1;
			var monyr = mondate.getFullYear();
				if (mody < 10){ mody = '0' + mody;}
				if (monmo < 10){ monmo = '0' + monmo;}
			var tuedate = new Date(passdate.valueOf() + (1 * 24 * 60 * 60 * 1000));
			var tudy = tuedate.getDate();
			var tuemo = tuedate.getMonth()+1;
			var tueyr = tuedate.getFullYear();
				if (tudy < 10){ tudy = '0' + tudy;}
				if (tuemo < 10){ tuemo = '0' + tuemo;}
			var weddate = new Date(passdate.valueOf() + (2 * 24 * 60 * 60 * 1000));
			var wddy = weddate.getDate();
			var wedmo = weddate.getMonth()+1;
			var wedyr = weddate.getFullYear();
				if (wddy < 10){ wddy = '0' + wddy;}
				if (wedmo < 10){ wedmo = '0' + wedmo;}
			var thurdate = new Date(passdate.valueOf() + (3 * 24 * 60 * 60 * 1000));
			var thdy = thurdate.getDate();
			var thurmo = thurdate.getMonth()+1;
			var thuryr = thurdate.getFullYear();
				if (thdy < 10){ thdy = '0' + thdy;}
				if (thurmo < 10){ thurmo = '0' + thurmo;}
			var fridate = new Date(passdate.valueOf() + (4 * 24 * 60 * 60 * 1000));
			var frdy = fridate.getDate();
			var frimo = fridate.getMonth()+1;
			var friyr = fridate.getFullYear();
				if (frdy < 10){ frdy = '0' + frdy;}
				if (frimo < 10){ frimo = '0' + frimo;}
			document.getElementById('beginDate').innerHTML = mody+"/"+monmo+"/"+monyr;
			document.getElementById('beginDateField').value = mody+"/"+monmo+"/"+monyr;
			document.getElementById('endDate').innerHTML = frdy+"/"+frimo+"/"+friyr;
			document.getElementById('FridayDate').innerHTML = frdy+"/"+frimo+"/"+friyr;
			document.getElementById('endDateField').value = frdy+"/"+frimo+"/"+friyr;
			document.getElementById('thursDate').innerHTML = thdy+"/"+thurmo+"/"+thuryr;
			document.getElementById('thursDateField').value = thdy+"/"+thurmo+"/"+thuryr;
			document.getElementById('wedsDate').innerHTML = wddy+"/"+wedmo+"/"+wedyr;
			document.getElementById('wedsDateField').value = wddy+"/"+wedmo+"/"+wedyr;
			document.getElementById('tuesDate').innerHTML = tudy+"/"+tuemo+"/"+tueyr;
			document.getElementById('tuesDateField').value = tudy+"/"+tuemo+"/"+tueyr;
			return true;
			}
		} 
	}
}

Here is the relevant HTML

<form id="Jaugeage" action="html_mail_process.php" method="post" name="jaugeage">
	<table width="100%">
		</tr>
			<td align="center"><b><i>PREVISIONS DE JAUGEAGE SEMAINE DU&nbsp;&nbsp;</i></b>
				<input type="text" size="12" maxlength="12" value="jj/mm/aaaa" name="startDate" tabindex="10" onKeyDown="if(event.keyCode==13) event.keyCode=9;" onChange="mondaycheck(this.value, this.form.txtFri);"/>
			</td>
  		</tr>
		<tr>
			<td align="center"><textarea cols="30" name="txtLundimorn" rows="5" tabindex="11"></textarea></td>
		</tr>
	</table>
</form>

Can anybody see what is causing the problem with returning to the date field, or offer me another solution.

[clueful]

I
The problem I have is that although the alert is given, the focus does not return to the correct field, it goes to the next field in the form sequence.

This is a common problem, solved by setting a timeout to focus the field. Having said that, alerting on blur (or on change) is generally regarded as hostile operation.