function getAjaxRequest() {

    var ajaxRequest;
    try{
        // Opera 8.0+, Firefox, Safari
        ajaxRequest = new XMLHttpRequest();
    } catch (e){
        // Internet Explorer Browsers
        try{
            ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try{
                ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e){
                // Something went wrong
                window.status = "Your browser does not support AJAX!";
                return null;
            }
        }
    }
    return ajaxRequest;

} // getAjaxRequest

function escapeHTML(str) {

    var div = document.createElement('div');
    var text = document.createTextNode(str);
    div.appendChild(text);
    return div.innerHTML;

} // escapeHTML

function validEmail(str) {

    return str.match("\\w+([-+.]\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*");

} // validEmail