AJAX div refresh just clearing div contents - php

Question

what i have is a list of posts on a page then each post has an icon to add to favorites (also has a watch button but it works the exact same to this) when clicked it calls the page with the script to add this post to ur favorites list in the database. (before using ajax i used a php redirect which returned to the previous page) when the page gets refreshed the database gets checked for what posts you have on your favorites list and will show the appropriate image depending on if its on ur favorites list or not.
When i click the link it appears to do what it should (go to the page and runs the update query to the database) but rather than refresh the div it just clears it. when i press f5 to refresh the page the image now displays the ticked image as it should so the query to the database is made when i click and the div gets kind of refreshed but it requires a proper refresh for it to display.
echo '<div id = "favwatchbox'.$ID.'">';
if($_SESSION['Valid'] == "True" ){
$userid = $_SESSION['ID'];
$check= "SELECT * from UserFavoritePost WHERE UserID='$userid' AND PostID='$ID'";
$resultcheck = $db->query($check);
$num_resultcheck = $resultcheck->num_rows;
$checklater= "SELECT * from UserViewLaterPost WHERE UserID='$userid' AND PostID='$ID'";
$resultchecklater = $db->query($checklater);
$num_resultchecklater = $resultchecklater->num_rows;
$prelogin = $_SERVER["REQUEST_URI"];
if($num_resultcheck >= 1)
{
echo "<a id = 'favdel".$ID."' href='#'><img id='Fav' title='Favorited' src='images/site-design/Favoritecheck.png'></a>";
?>
<script>
$(function() {
$("#favdel<?echo$ID;?>").click(function(evt) {
$("#favwatchbox<?echo$ID;?>").load("sql-scripts/deletefavorite.php?post=<?echo $ID;?>&user=<?echo $userid;?>&pre=<?echo $prelogin;?>")
evt.preventDefault();
})
})
</script>
<?
}
else
{
echo "<a id = 'favadd".$ID."' href='#'><img id='Fav' title='Mark as Favorite' src='images/site-design/Favorite.png'></a>";
?>
<script>
$(function() {
$("#favadd<?echo$ID;?>").click(function(evt) {
$("#favwatchbox<?echo$ID;?>").load("phpincludes/markasfavorite.php?post=<?echo $ID;?>&user=<?echo $userid;?>&pre=<?echo $prelogin;?>")
evt.preventDefault();
})
})
</script>
<?
}
}
the page for deleting from favourites
<?php
include '../phpincludes/dbconnection.php';
$userid = $_GET['user'];
$postid = $_GET['post'];
$query = "DELETE FROM UserFavoritePost WHERE UserID='$userid' And PostId='$postid'";
$result = $db->query($query);
$presubmit = $_GET['pre'];
if($presubmit == "/myaccount.php")
{
header("location:".$presubmit."");
}
?>
i have included an img src in the delete from favorites php file and now when you click it does the update and updates the image but when i click the link again to re add to my favorites it just brings me to the top of the page. if i refresh and click it will then run the add script but it still isnt refreshing the div properly