Problem with row update

I'm trying to set up a script to be able to edit the fields of a database row. The update script I have is changing all of the info in all the rows instead of just one row. Heres what I'm using.
This is set up to change employee data in a mysql database.

The form data, passes an employee number and email address to "update.php".

<form action="update.php" method="post">
Employee Number
<input type=text size=10 name="empnumberedit">
Email address
<input type=text name="emailedit" size=30>

The update script.
[<?
include("dbinfo.inc.php");
$dbh=mysql_connect ("localhost", "$username", "$password") or die ('I cannot connect to the database because: ' . mysql_error());
mysql_select_db ("$database");
$query=("SELECT * FROM contacts WHERE empnumber='$empnumberedit' AND email='$emailedit'");

$result=mysql_query($query);
$num=mysql_num_rows($result);
mysql_close();

$i=0;
while ($i < $num) {
$id=mysql_result($result,$i,"id");
$empnumber=mysql_result($result,$i,"empnumber");
$fname=mysql_result($result,$i,"fname");
$lname=mysql_result($result,$i,"lname");
$dept=mysql_result($result,$i,"dept");
$email=mysql_result($result,$i,"email");
$phone=mysql_result($result,$i,"phone");


?>

<form action="updated.php">
<input type="hidden" name="ud_id" value="<? echo "$id"; ?>">
<font face=verdana, times size=2><b>
Employee Number: <br>
<input type="text" name="ud_empnumber" value="<? echo" $empnumber"?>"><br>
First Name:<br>
<input type="text" name="ud_fname" value="<? echo "$fname"?>"><br>
Last Name:<br>
<input type="text" name="ud_lname" value="<? echo "$lname"?>"><br>
Department/Position:<br>
<input type="text" name="ud_dept" value="<? echo "$dept"?>"><br>
Email:<br>
<input type="text" name="ud_email" value="<? echo "$email"?>"><br>
Phone:<br>
<input type="text" name="ud_phone" value="<? echo "$phone"?>"><br>
<input type="Submit" value="Update">
</form></td>

<?
++$i;
}
?>]

And then "updated.php".
[<?
include("dbinfo.inc.php");
$dbh=mysql_connect ("localhost", "$username", "$password") or die ('I cannot connect to the database because: ' . mysql_error());
mysql_select_db ("$database");

$query=("UPDATE contacts SET empnumber='$ud_empnumber', fname='$ud_fname', lname='$ud_lname', dept='$ud_dept', email='$ud_email', phone='$ud_phone'");
@mysql_select_db($database) or die( "Unable to select database");
mysql_query($query);
echo "Contact Info Updated";
mysql_close();
echo "<meta http-equiv="refresh" content="0; url=changed.html" />n";
?>]
Seems like I'm missing something, but I don't know what. Instead of updating just one row, it updates all of the rows, the only thing that doesnt change is the "id" field. Any ideas?

In your update query you must specify which row you want to update. You can do this in WHERE clause.

I tried this, using single quotes and no quotes in the where statement, but now it isn't changing anything.

[ $query=("UPDATE contacts SET empnumber='$ud_empnumber', fname='$ud_fname', lname='$ud_lname', dept='$ud_dept', email='$ud_email', phone='$ud_phone' WHERE id='$id'");]

?????

the name of the hidden field that holds the id on the form is ud_id, so the query should look like this.

$query=("UPDATE contacts SET empnumber='$ud_empnumber', fname='$ud_fname', lname='$ud_lname', dept='$ud_dept', email='$ud_email', phone='$ud_phone' WHERE id='$ud_id'");]


you need to reference $ud_id in the where statement, not just $id

That did it...knew I was missing something. Thnx alot, youre a lifesaver.