this.obj.firstChild' is null or not an object

Suite and Optimus Suite 5
#1

when i run grid in IE8 , it throws this error
Message: ‘this.obj.firstChild’ is null or not an object
Line: 150
Char: 305
Code: 0

my index page is

#2

Your client side code is correct. Will this issue occur of you commit mygrid.loadXML(“phpbb_users_xml.php”); ?

#3

may be my xml page is

<?php //set content type and xml tag header("Content-type:text/xml"); print("<?xml version=\"1.0\"?>"); 
    //define variables from incoming values
    if(isset($_GET["posStart"]))
        $posStart = $_GET['posStart'];
    else
        $posStart = 0;
    if(isset($_GET["count"]))
        $count = $_GET['count'];
    else
        $count = 100;

    //connect to database
    $link = mysql_connect("localhost", "root", "sasi");
    $db = mysql_select_db("Phpbb3_default"); //coolmoco_db

    //create query to products table
    $sql = "SELECT  * FROM phpbb_users  WHERE user_type='0' ORDER BY region";

    //if this is the first query - get total number of records in the query result
    if($posStart==0){
        $sqlCount = "Select count(*) as cnt from ($sql) as tbl";
        $resCount = mysql_query ($sqlCount);
        $rowCount=mysql_fetch_array($resCount);
        $totalCount = $rowCount["cnt"];
    }

    //add limits to query to get only rows necessary for the output
    $sql.= " LIMIT ".$posStart.",".$count;

    //query database to retrieve necessary block of data
    $res = mysql_query($sql);

    //output data in XML format   
    print("<rows total_count='".$totalCount."' pos='".$posStart."'>");   
    while($row=mysql_fetch_array($res)){
	print("<row id='".$row['user_id']."'>");
		    print("<cell>");
                print($row['region']);  
            print("</cell>");
            print("<cell>");
                print($row['nickname']);  
            print("</cell>");
			print("<cell>");
                print($row['addscore']);    
            print("</cell>");
			print("</row>");
			}
    print("</rows>");
?>