function init_req() {
    var xmlHttp;
        try {
	    // Firefox, Opera 8.0+, Safari
    	    xmlHttp = new XMLHttpRequest();
	}
	catch (e) {
	    // Internet Explorer
	    try {
	        xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
	    }
	    catch (e) {
	        try {
		    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
	        }
	        catch (e) {
	    	    alert("Your browser does not support AJAX!");
		return false;
		}
	    }
	}
    return xmlHttp;
}