Here's my PHP code:

<?php
include("../connect.php");
ob_start();
if($_POST["mode"]=="admin")
{
admin_login();
}
else if($_GET["mode"]=="logout")
{
admin_logout();
}
else
{
main();
}
function admin_logout()
{
session_unset();
session_destroy();
$GLOBALS["msg"]="You are logged out";
main();
exit;
}
function main()
{
?>
<script src="config/jquery-latest.js"></script>
<script type="text/javascript" src="config/jquery.validate.js"></script>
<style type="text/css">
label.error { float: none; color: red; padding-left: .5em; vertical-align: top; }
</style>
<script>
$(document).ready(function(){
$("#form1").validate();
});
</script>
<table width="475" border="0" align="center" cellpadding="0" cellspacing="0" style="border:thin solid #000000;">
<tr>
<td align="center" style="border-bottom:thin solid #000000;"><h2>Welcome To Admin Panel</h2></td>
</tr>
<tr>
<td width="475">
<form id="form1" name="form1" id="form1" class="cmxform" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<input type="hidden" name="mode" value="admin">
<table width="334" border="0" align="center" cellpadding="5" cellspacing="0">
<tr>
<td>&nbsp;</td>
<td><b><?php if(isset($GLOBALS["msg"])) { echo $GLOBALS["msg"]; }?></b></td>
</tr>


<form method="post" action="http://localhost/admin/admin.php">
<tr>
<td><b>Account Type:</td> <td><select name="accttype"></b>
<option value="1">Admin</option>
<option value="2">Team Manager</option>
<option value="3">Human Resources</option>
<option value="4">Employee</option> </td>
</select>
</tr>

</form>
<tr>
<td><b>User Name: </b></td>
<td>
<input type="text" name="username" class="required" />
</td>
</tr>
<tr>
<td><b>Password:</b></td>
<td>
<input type="password" name="password" class="required" />
</td>
</tr>
<tr>
<td>&nbsp;</td>
<td>
<input type="submit" name="login" value="login"/>
</td>
</tr>
</table>
</form>
</td>
</tr>
</table>
<?php
}
function admin_login()
{
$sql="select * from admin where username='".$_POST[username]."' and password='".$_POST[password]."'";

$query=mysql_query($sql);
$row=mysql_fetch_array($query);
$num=mysql_num_rows($query);
if($num==1)
{
$_SESSION["user_id"]=$row["username"];
header("location:admin.php");
exit;
}
else
if($num==2)
{
$_SESSION["user_id"]=$row["username"];
header("location:TM.php");
exit;
}
else
{
$GLOBALS["msg"]="<font color=red>Wrong Username or Password</font>";
main();
exit;
}
}
ob_end_flush();
?>

Question:
1) Why does the autofill from Username and Password doesn't turn off even if I turn it off on the browser?

2)How do I filter login? (example: when logged choosing the Team Managers from drop down menu, it will go to a certain page)

For turning off autofill feature of the textbox , set the autocomplete property of the textbox to False or NO.
For filtering user login, what you are trying to do means that you have only two team managers who have the same username and password which I dont think is the case.so what you can do is to create a pagename field in your users table and depending on the category of the user you are registering or creating save the name of the page you want the user to be redirected to when the user logs in. so after registering the user and the user logs in using the username and the password you retrieve the corresponding redirecting page name from the users table and then pass the page name to the header() function.hope it helps

seems that I can't find the text box property. Is it on the java script? co'z I've just downloaded the java script from the net.

Filtering user login: Is it possible to filter user_id ? I mean if user_id(1) logs in, he/she will be redirected to webpage(A). Then when user_id(2) logs in, he/she will be redirected to webpage(B). Is it possible in PHP? how?