//Create a boolean variable to check for a valid Internet Explorer instance.
        var xmlhttp = false;

        //Check if we are using IE.
        try {
                //If the Javascript version is greater than 5.
                xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
                //If not, then use the older active x object.
                try {
                        //If we are using Internet Explorer.
                        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (E) {
                        //Else we must be using a non-IE browser.
                        xmlhttp = false;
                }
        }

        //If we are using a non-IE browser, create a javascript instance of the object.
        if (!xmlhttp && typeof XMLHttpRequest != 'undefined') {
                xmlhttp = new XMLHttpRequest();
        }