ajax freezing my IE6 IE7 browsers

[noamkrief]

Hi, i've been having this crazy inconsistent issue with Ajax / php and IE.

 

Here is my code:

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;
};



function savemyform(f) {





		var i = 0
		var param = "";
		while (i < f.elements.length) {

			// alert(f.elements[i].type);
			if (f.elements[i].type == 'submit' || f.elements[i].type == 'button' || f.elements[i].type == undefined) {

			} else {

				if (f.elements[i].type == 'checkbox') {
					if (f.elements[i].checked == true) {

						param = param + f.elements[i].name + "=" + f.elements[i].value +"&"

					}
				} else {
					param = param + f.elements[i].name + "=" + encodeURIComponent(f.elements[i].value) +"&"
				}
			}
			i++;

		}


			 var req = Inint_AJAX();
			 req.onreadystatechange = function () {
				  if (req.readyState==4) {



					   if (req.status==200) {
							try {
																			if (req.responseText == 1) {
											document.getElementById('savemessage').innerHTML = 'saved succesfully...';
										} else
										if (req.responseText == 2) {
											alert('Duplicate. Saving failed!');
										} else {
											alert('Saving Failed... Timeout Error.');
										}

										setTimeout('deletesetmessage()', 500)


								 } catch(e) { }
					   }
				  }
			 };



			var url = "./save.php";

			req.open("POST", url, true);

			//Send the proper header information along with the request
			req.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
			req.setRequestHeader("Content-length", param.length);
			req.setRequestHeader("Connection", "close");
			req.send(param);


}

function deletesetmessage() {

	document.getElementById('savemessage').innerHTML = "";
}

 

 

 

So, when i click "save" in the webpage, there is a div where it displays "saved succesfully..."

Sometimes when the internet connection is slow like on a verizon EVDO card, nothing happens when i click the save button. If I do this more than twice, IE freezes completely and the entire web application crashes. I have to open new IE and login from scratch.

 

I think my init_AJAX needs a timeout perhaps? Right now it would loop for all eternaty and i've read that IE can only handle 2 requests at the same time.

 

I'd really appreciate input - i'm pretty new with ajax and don't really understand the javascript behind it.

Thanks

Noam

[noamkrief]

I think I got it, but let me know if it makes any sense. Once I removed this line: req.setRequestHeader("Connection", "close");  I couldn't replicate my issue any more.

 

So I did some google searches on this string "setRequestHeader("Connection", "close");" and found many sites talking about IE hanging. What a conincedense right???

 

Can anyone explain why this line would have been the issue?

Thanks