ทำไม Alert ไม่ทำงานอ่ะครับ งงมาก แก้มา 1 วันแล้ว ยังไม่ได้เลย :(

function insert_member(){
	var username = $("#name").val();
    var userpass = $("#pass").val();
	var xxml = null;
	var data = "name=" + username + "&pass=" + userpass;
	xxml = GetXMLHttp();
	xxml.onreadystatechange=function(){
		if ( xxml.readyState == 4 ){
			document.getElementById("ajax_home").innerHTML = xxml.responseText;
		}else{
			pageloadprocess( "ajax_home" );
		}
	};
	xxml.open("POST", "submit.php" , true );
	xxml.setRequestHeader ( "Content-Type", "application/x-www-form-urlencoded" );
	xxml.send(data);
}

<?
$username = $_POST["name"];
$userpass = $_POST["pass"];
$objConnect = mssql_connect($host_ip,$host_user,$host_pass) or die("Error Connect to Database");
$objDB = mssql_select_db("member");
$strSQL = "INSERT INTO user(Name,Pass) values ('$username','$userpass') ";
$objQuery = mssql_query($strSQL);
if($objQuery)
{
	echo '<script language="javascript">';
	echo 'alert("Ok")';
	echo '</script>';
}
else
{
	echo '<script language="javascript">';
	echo 'alert("Error")';
	echo '</script>';
}
mssql_close($objConnect);
?>

echo "<script language='javascript'>alert('OK');</script>";

$.ajax({ // create an AJAX call...
				data: { id : idx }, // get the form data
				type: 'POST', // GET or POST
				url: 'farm_edit.php', // the file to call
				success: function(response) { // on success..
                                   if(response == true){
                                                alert("OK");
						$('#mycontent').html(response); // update the DIV
                                   }else{
                                               alert("FAIL");
                                   }
				}
			});
			return false; // cancel original event to prevent form submitting