From the html sample you gave, I don't see how this is going to work at all....
First of all your checking if the value was sent using the POST method:
if (isset($_POST['yesdelete'])) {
Then you're pulling the actual value from the passed querystring (GET)
$id_to_delete = $_GET['yesdelete'];
If for some reason this is actually correct, the value you're sending is "[FONT=Courier New]Submit[/FONT]"
<input type="submit" [COLOR="#FF0000"]name="yesdelete"[/COLOR] id="deleteid" [COLOR="#FF0000"]value="Submit"[/COLOR] />
Also, I would remove the "LIMIT 1" from the DELETE SQL statement, I don't think that's valid (I stand to be corrected)?