I'm using the following AJAX code to send GET vars to my processing PHP file. This works great as is except that it will not accept a *&* (AND symbol) in the text input. It trys to pass what is after the *&* as a new GET var. I totaly get what is happening, just don't get how to fix it. I hope my example code is sufficient.

HTML:
Code:
<input type="text" class="inputbox" value="pb&j" id="input_name" name="input_name" onblur="javascript:makeRequest('my_file.php?new=',this.value);"/>
Javascript:
Code:
var http_request = false;
function makeRequest(url, parameters) { //alert(parameters)
	http_request = false;
	if (window.XMLHttpRequest) { // Mozilla, Safari,...
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {
			// set type accordingly to anticipated content type
			//http_request.overrideMimeType('text/xml');
			http_request.overrideMimeType('text/html');
		}
	} else if (window.ActiveXObject) { // IE
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
		}
	}
	if (!http_request) {
		alert('Cannot create XMLHTTP instance');
		return false;
	}
	http_request.onreadystatechange = alertContents;

	// FOR POST VARS
	//http_request.open('POST', url, true);
	//http_request.send(parameters);

	// FOR GET VARS
	http_request.open('GET', url + parameters + "&time=" + get_date(), true);
	http_request.send(null);
}

function alertContents() {
if (http_request.readyState == 4) {
 if (http_request.status == 200) {
    //alert(http_request.responseText);
    result = http_request.responseText;
    document.getElementById('myspan').innerHTML = result;
 } else {
    alert('There was a problem with the request.');
 }
}
}