//**********************************************************************
// Name			: createXMLHttpRequest
// Description	: Constructs the appropriate flavor of XMLHttpRequest 
//				  object (for use in Ajax calls) based on the browser
//				  type.  If the browser is too old and does not support
//				  Ajax, this method will return null.
// Input		: N/A
// Output		: The generated request object, or null if this browser
//				  does not support Ajax
//**********************************************************************
function createXMLHttpRequest() {
    var request;
	
	try {
		//Firefox, Safari, Opera 8.0+
		request = new XMLHttpRequest();
	} 
	catch (e) {		
		try {
			//Internet Explorer 6.0+
			request = new ActiveXObject("Msxml2.XMLHTTP");
		} 
		catch (e) {
			try {
				//Internet Explorer 5.5+
				request = new ActiveXObject("Microsoft.XMLHTTP");
			} 
			catch (e) {
				//No support for Ajax
				return null;
			}
		}
	}
    
    return request;
}