Ajax ทำงานไม่ได้ใน IE7 ทำไงดีช่วยด่วน ขอแบบละเอียด

<script language="javascript">

var p="";
var t="";
var a="";
var total;

function setP(pid){
	p = pid;
}
function setT(tid){
	t = tid;
	//alert(t);
}
function setA(aid){
	a = aid;
}

var HttPRequest = false;
function doCallAjax(Mode) {
		
			  if (window.XMLHttpRequest) { // Mozilla, Safari,...
				 HttPRequest = new XMLHttpRequest();
				 if (HttPRequest.overrideMimeType) {
					HttPRequest.overrideMimeType('text/html');
				 }
			  } else if (window.ActiveXObject) { // IE
				 try {
					HttPRequest = new ActiveXObject("Msxml2.XMLHTTP");
				 } catch (e) {
					try {
					   HttPRequest = new ActiveXObject("Microsoft.XMLHTTP");
					} catch (e) {}
				 }
			  } 
			  
			  if (!HttPRequest) {
				 alert('Cannot create XMLHTTP instance');
				 return false;
			  }
			  var url = 'tran_add.php';
			  var pmeters = "promis_num=" + encodeURI( document.getElementById("txtpromis_num").value) +
							"&bDate=" + encodeURI( document.getElementById("txtdate").value ) +
							"&date_promis=" + encodeURI( document.getElementById("txtdate_promis").value ) +
							"&member_id=" + encodeURI( document.getElementById("txtmember_id").value ) +
							"&or_name_str=" + encodeURI( document.getElementById("txtname_str").value ) +
							"&or_sur_str=" + encodeURI( document.getElementById("txtor_sur_str").value ) +
							"&address=" + encodeURI( document.getElementById("txtaddress_str").value ) +
							"&number=" + encodeURI( document.getElementById("txtnumber").value ) +
							"&moo=" + encodeURI( document.getElementById("txtmoo").value ) +
							"&tanon=" + encodeURI( document.getElementById("txttanon").value ) +
							"&tumbon1=" + encodeURI( document.getElementById("txttumbon_1").value ) +
							"&amphur1=" + encodeURI( document.getElementById("txtamphur_1").value ) +
							"&province1=" + encodeURI( document.getElementById("txtprovince_1").value ) +
							"&Time=" + encodeURI( document.getElementById("txttimee").value ) +
							"&or_name_end=" + encodeURI( document.getElementById("txtor_name_end").value ) +
							"&or_cargo=" + encodeURI( document.getElementById("txtor_cargo").value ) +
							"&or_name_cargo=" + encodeURI( document.getElementById("txtor_name_cargo").value ) +
							"&or_weight_cargo=" + encodeURI( document.getElementById("txtWeight").value ) +
							"&or_company_end=" + encodeURI( document.getElementById("txtor_company_end").value ) +
							"&or_addres_end=" + encodeURI( document.getElementById("txtor_addres_end").value ) +
							"&moo_end=" + encodeURI( document.getElementById("txtmoo_end").value ) +
							"&tanon_end=" + encodeURI( document.getElementById("txttanon_end").value ) +
							"&or_provincee=" + encodeURI( p) +//document.getElementById("province").value 
							"&or_amphur=" + encodeURI(a) +//document.getElementById("amphur").value
							"&or_tumbon=" + encodeURI(t) + //document.getElementById("tumbon").value 
							"&or_select_car=" + encodeURI( document.getElementById("txtor_car").value ) +
							"&date_due=" + encodeURI( document.getElementById("txtdate_due").value ) +
							"&or_payprogram=" + encodeURI( total ) +
						//	"&tor_status=" + encodeURI( document.getElementById("txtor_status").value ) +
							"&tMode=" + Mode;
				//alert(pmeters);
				HttPRequest.open('POST',url,true);
	
				HttPRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
				HttPRequest.setRequestHeader("Content-length", pmeters.length);
				HttPRequest.setRequestHeader("Connection", "close");
				HttPRequest.send(pmeters);
				
				
				HttPRequest.onreadystatechange = function()
				{
	
					 if(HttPRequest.readyState == 3)  // Loading Request
					  {
					   document.getElementById("mySpan").innerHTML ="<image src='pictu/indicator_flower.gif'>";
					  }
	
					 if(HttPRequest.readyState == 4) // Return Request
					  {
					  	window.location = 'AjaxPHPRegister3.php';
					}
					else
					{
						document.getElementById("mySpan").innerHTML = HttPRequest.responseText;
					}
					{
					 // alert(HttPRequest.responseText);
				//	   document.getElementById("mySpan").innerHTML = HttPRequest.responseText;
					  /* document.getElementById("txtpromis_num").value = '';
					   document.getElementById("txtmember_id").value = '';
					   document.getElementById("txtdate").value = '';
					   document.getElementById("txtdate_promis").value = '';
					   document.getElementById("txttimee").value = '';
					   document.getElementById("txtname_str").value = '';
					   document.getElementById("txtor_sur_str").value = '';
					   document.getElementById("txtaddress_str").value = '';
					   document.getElementById("txtnumber").value = '';
					   document.getElementById("txtmoo").value = '';
					   document.getElementById("txttanon").value = '';
					   document.getElementById("txttumbon_1").value = '';
					   document.getElementById("txtamphur_1").value = '';
					   document.getElementById("txtprovince_1").value = '';
					   document.getElementById("txttimee").value = '';
					   document.getElementById("txtor_name_end").value = '';
					   document.getElementById("txtcargo").value = '';
					   document.getElementById("txtor_name_cargo").value = '';
					   document.getElementById("txtWeigth").value = '';
					   document.getElementById("txtor_company_end").value = '';
					   document.getElementById("txtor_address_end").value = '';
					   document.getElementById("txtmoo_end").value = '';
					   document.getElementById("txttanon_end").value = '';
					   document.getElementById("txtor_province").value = '';
					   document.getElementById("txtor_select_car").value = '';
					   document.getElementById("txtdate_due").value = '';
					   document.getElementById("txtr_payprogram").value = '';
					   document.getElementById("txtor_status").value = '';*/
					  }
					
				}
			
	   }
// Start XmlHttp Object

function chkFrm(){
	
		var txtaddress_str = document.getElementById("txtaddress_str").value;
		var txttumbon_1 = document.getElementById("txttumbon_1").value;
		var txtamphur_1 = document.getElementById("txtamphur_1").value;
		var txtor_name_end = document.getElementById("txtor_name_end").value;
		var txtor_name_cargo = document.getElementById("txtor_name_cargo").value;
		var txtor_cargo = document.getElementById("txtor_cargo").selectedIndex;	
		var txtor_name_cargo = document.getElementById("txtor_name_cargo").value;
		var txtWeight = document.getElementById("txtWeight").value;
		var txtor_company_end = document.getElementById("txtor_company_end").value;
		
		
		
		if(txtaddress_str==""){
					alert("กรุณากรอกสถานที่สินค้าขึ้น");
					return;
		}
		else if(txttumbon_1==0){
					alert("กรุณาระบุตำบล");
					return;
		}
		else if(txtamphur_1==0){
					alert("กรุณาระบุอำเภอ");
					return;
		}
		else if(txtor_name_end==""){
					alert("กรุณากรอกชื่อผูู้รับ");
					return;
		}
		else if(txtor_cargo==0){
					alert("กรุณาระบุประเภทสินค้า");
					return;
		}
		else if(txtor_name_cargo==""){
					alert("กรุณากรอกระบุชื่อสินค้า");
					return;
		}
		else if(txtWeight==""){
					alert("กรุณากรอกน้ำหนัก");
					return;
		}		
		else if(txtor_company_end==""){
					alert("กรุณากรอกชื่อลงสินค้า");
					return;
		}		
		else		
			doCallAjax();

}
function uzXmlHttp(){
    var xmlhttp = false;
    try{
        xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    }catch(e){
        try{
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }catch(e){
            xmlhttp = false;
        }
    }
 
    if(!xmlhttp && document.createElement){
        xmlhttp = new XMLHttpRequest();
    }
    return xmlhttp;
}
// End XmlHttp Object
 
function select_data(id,value1){
    var result;
    var url = 'amphur.php?id=' + id + '&value1='+value1 ;    
	//alert(url);
    xmlhttp = uzXmlHttp();
    xmlhttp.open("GET", url, false);
    xmlhttp.send(null);
	document.getElementById(id).innerHTML =  xmlhttp.responseText;
	
	//document.all.tumbon.style.display='none';

	  if(id=='amphur'){
	  		var url = 'amphur.php?id=tumbon&value1=' ;    
			//alert(url);
			xmlhttp = uzXmlHttp();
			xmlhttp.open("GET", url, false);
			xmlhttp.send(null);
			//alert(xmlhttp.responseText);
	  		document.getElementById('tumbon').innerHTML =  xmlhttp.responseText;
	  }
}

function strOK(num){
    // ??? form ? num1,num2
  /*  var province = document.form2.txtprovince_1.value;
   var amphur = document.form2.txtamphur_1.value;
   var tumbon = document.form2.txttumbon_1.value;*/
       var province = p;
   var amphur = a;
   var tumbon = t;
   
   var txtWeight=document.form2.txtWeight.value;
    var result;
	var url = 'ok.php?province=' + province + '&amphur='+ amphur + '&tumbon=' +tumbon + '&txtWeight=' + txtWeight;    
	//alert(url);
    xmlhttp = uzXmlHttp();
    xmlhttp.open("GET", url, false);
    xmlhttp.send(null);
    result = xmlhttp.responseText;
	//alert(result);
	var stemp = xmlhttp.responseText;
	var temp = stemp.split("//\\");
	total=temp[1];
	//alert(total);
    document.getElementById('result2').innerHTML =  temp[0];
}

window.onLoad=select_data("province",''); 
window.onLoad=select_data("amphur", ''); 
window.onLoad=select_data("tumbon", ''); 
</script>
<script language="javascript">
function Inint_AJAX() {
   try { return new ActiveXObject("Msxml2.XMLHTTP"); } catch(e) {} //IE
   try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch(e) {} //IE
   try { return new XMLHttpRequest(); } catch(e) {} //Native Javascript
   alert("XMLHttpRequest not supported");
   return null;
};

//dochange จะถูกเรียกเมื่อมีการเลือก รายการ Combobox ซึ่งจะทำให้ไปเรียก AJAX เพื่อร้องขอข้อมูลถัดไปจาก Server
function dochange(src, val) {
  var req = Inint_AJAX();
  req.onreadystatechange = function () {
    if (req.readyState==4) {
      if (req.status==200) {
        document.getElementById(src).innerHTML=req.responseText; //รับค่ากลับมา
      }
    }
  };
  req.open("GET", "province.php?data="+src+"&val="+val); //สร้าง connection
  req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); // set Header
  req.send(null); //ส่งค่า
}

//เรียกครั้งแรกไปทำการโหลด อำเภอ มาแสดง
window.onLoad=dochange('txtamphur_1', -1);
</script>