username and password verification

[ravi951]

hi all,
my database name is "test".in the "test" database
i have created a table name called "log" which has two fields
namely username and password.
i have given username as "admin" and password as "admin123".
now i have written one code using php so that when i click the submit button both the username as "admin" and password as "admin123" gets matched then it should direct to the next page...
tell me how to check whether username and passwords are matching and if it matches it must point to the action part what we give in <form method="POST" action="www.php">
kindly tell me what i must add to the below program.....
below is the code in php......

<?php
$host="localhost";  
$username="root";  
$password="";  
$db_name="test"; 
$tbl_name="log"; 

mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB");
 
$myusername=$_POST['myusername']; 
$mypassword=$_POST['mypassword'];

$myusername = stripslashes($myusername);
$mypassword = stripslashes($mypassword);
$myusername = mysql_real_escape_string($myusername);
$mypassword = mysql_real_escape_string($mypassword);

$sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
$result=mysql_query($sql);

// Mysql_num_row is counting table row
$count=mysql_num_rows($result);
// If result matched $myusername and $mypassword, table row must be 1 row
if($count==1)
{
// Register $myusername, $mypassword and redirect to file "login_success.php"
session_register("myusername");
session_register("mypassword"); 
header("location:www.php");
}
else 
{
echo "Wrong Username or Password";
}
?>

[JShor]

Name your submit button something, and check if the submit button (which is technically an input) has been POSTed.

<?php
$host="localhost";  
$username="root";  
$password="";  
$db_name="test"; 
$tbl_name="log"; 

mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB");
 
$myusername=$_POST['myusername']; 
$mypassword=$_POST['mypassword'];

$myusername = stripslashes($myusername);
$mypassword = stripslashes($mypassword);
$myusername = mysql_real_escape_string($myusername);
$mypassword = mysql_real_escape_string($mypassword);

if(isset($_POST['submit'])) {

$sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
$result=mysql_query($sql);

// Mysql_num_row is counting table row
$count=mysql_num_rows($result);
// If result matched $myusername and $mypassword, table row must be 1 row
if($count==1)
{
// Register $myusername, $mypassword and redirect to file "login_success.php"
session_register("myusername");
session_register("mypassword"); 
header("location:www.php");
}
else 
{
echo "Wrong Username or Password";
}

}
?>

Then just set your submit button with the name attribute set to submit.

<input type="submit" name="submit" value=" Log in " />