[RESOLVED] function not working

[vbbit]

I need some help, I tried to develop this function. Say I have a database that has 2 colums for now.

row1
column1(id) - 1
column2 - test

row2
colum1(id)-2
column2 - test, testing, tester

I coded up this function to retrieve that information seperately. For example, if a user has a URL query string with user=test, then when the query run, the user should get outputs of the id's "1 and 2", but if the user=testing, then the output should be only "1"... but my logic is not working.

$userid = $_GET['user'];

   $sql = "SELECT * FROM interest";
   $return = mysql_query($sql) or die ("Unable to query" . mysql_error());
   while ($col = mysql_fetch_assoc($return))
   {
         $values = "{$col['Interested_ID']}";
            $test = explode(",", $values);
            for ($i=0; $i<=3; $i++)
            {
                //echo $test[$i];
                //echo "<br>";
                if ($test[$i] = $userid)

                //{
                // find out who is interested in that user
                $qry = "SELECT UserID FROM interest WHERE Interested_ID = '$test[$i]'";
                $result = mysql_query($qry) or die ("Unable to query" . mysql_error());
                while ($row = mysql_fetch_assoc($result))
                {
                      $value = "{$row['UserID']}";
                      echo $value;
                      echo "<br>";
                      exit;
                      //exit;
                }
                //}

            }