http_request failing between sites

[empiresolutions]

im trying to call a page on "Server B" from "Server A" using http_request method. the problem is the request fails at http_request.op en(). Below is the very basic code im using that can be found everywhere online.

Code Calling from a page on Server (site) A. Requesting URL is on Server (site) B

makeRequest('http://www.sitename.com/ajax_insert.php?field_name=test&field_value=',this.value);

This is the code in the makeRequest() function which is on Server (site) A.

function makeRequest(url, parameters) {

	http_request = false;
	if (window.ActiveXObject) { // IE
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
		}
	} else if (window.XMLHttpRequest) {// Mozilla, Safari,...xmlHttpReq.overrideMimeType
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {
			// set type accordingly to anticipated content type
			http_request.overrideMimeType('text/xml');
		}else{ alert('Did not create *http_request.overrideMimeType*'); return false; }
	} 

	if (!http_request) {

		alert('Cannot create XMLHTTP instance');
		return false;

	}

	http_request.onreadystatechange = alertContents;

	// FOR GET VARS
	http_request.open('GET', url + parameters, true);
	http_request.send(null);
	
}

So what am i missing? How can i get the http_request to process a page on another server (site). FYI, outside this application, my code as written works fine.

Thank you much for all the help.

[rnd me]

you can't. it's not allowed.

[gits]

that's right ... you may have a look here too ...

kind regards