เขียน AJAX แล้วไม่สามารถรันบน google chrome ได้คะ รบกวนชี้แนะด้วยนะคะ

   <script language="javascript">
function shipping(type) {
document.getElementById('shipping').innerHTML="";
		var product;
            if (window.ActiveXObject) {
                product = new ActiveXObject("Microsoft.XMLHTTP");
            } 
            else if (window.XMLHttpRequest) {
                product = new XMLHttpRequest();                
            }
			product.onreadystatechange = function()
				{
				 		  if(product.readyState == 4) {
									document.getElementById('shipping').innerHTML = product.responseText;   
   						 }
				}
		product.open("GET","ship_cal.php?ship_type="+type,true);		
		document.getElementById('next').innerHTML="<input type='submit' name='submit' id='submit' value='หน้าถัดไป' >";
		product.send(null);
        }
	function openfile(file){
	window.location=file;
	}
</script>

 <?php 
		include("../../include/connect.php");
		$sql="select * from shipping";
		$query=mysql_query($sql);
		$num=mysql_num_rows($query);
		for($i=0;$i<$num;$i++){
		$rs=mysql_fetch_array($query);
		echo "<p><input type='radio' name='RadioGroup1' value='$rs[id_ship]' id='RadioGroup1_0' onfocus=\"shipping('$rs[id_ship]')\" />$rs[type_ship]</p>";
		}
		?>
<p align="center">
        <div id="shipping" align="center"></div> //แสดงราคาค่าจัดส่ง
        </p>
          <form id="form1" name="tran" method="post" action="shipadd.php">
              <table width="100%" border="0" cellspacing="10" cellpadding="10">
                <tr>
                  <td align="center"><table width="260" border="0" cellspacing="0" cellpadding="0">
                      <tr>
                        <td width="60"><input type="button" name="button" id="button" value="ก่อนหน้า" onclick="openfile('basket.php')"></td>
                        <td width="100"><input type="button" name="button2" id="button2" value="เลือกสินค้าเพิ่ม" onclick="openfile('../../index.html')"></td>
                        <td width="100"><div id="next"></div></td> //แสดงปุ่ม
                      </tr>
                  </table></td>
                </tr>
              </table>
          </form>