function getRequest() {
    var req = null;
    if (window.XMLHttpRequest) {
        req = new XMLHttpRequest();
    } 
    else if (window.ActiveXObject) {
        try {
            req = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try {
                req = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
        }
    }
    return req;
}

function sendQueryEmail() { 
    if (!validateQueryForm()) {
        alert("Sie muessen alle angegebenen Felder korrekt ausfuehlen!");
        return false;
    } 
    
    var req = getRequest();
    var topic = encodeURIComponent(document.email_form.topic.value);
    var name  = encodeURIComponent(document.email_form.name.value);
    var email = encodeURIComponent(document.email_form.email.value);
    var email_clear = document.email_form.email.value;
    var text  = encodeURIComponent(document.email_form.textarea.value);
    var params = "topic="+topic+"&name="+name+"&email="+email+"&textarea="+text;
    var url = "index.php?maintenanceAJAX=sendEmail";
    
    req.open("POST", url, true);
    //Send the proper header information along with the request
    req.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    req.setRequestHeader("Content-length", params.length);
    req.setRequestHeader("Connection", "close");

    req.onreadystatechange = function()
    { 
        if(req.readyState == 4) {   
            if(req.status == 200) {
                alert("Die eMail wurde erfolgreich an "+email_clear+" und die Buchhandlung Losch verschickt!");
               //DEBUG:  alert(req.responseText);
            } else {
                alert("Es ist eine Fehler bei dem Versand der eMail aufgetreten. Versuchen Sie es erneut!");
                document.getElementById("page").innerHTML="<h2>Error occurs!</h2>";
            }   
        } 
    }; 
    req.send(params); 
}

function validateQueryForm() {
    //alert("*"+document.getElementById("textarea").value+"*");
    if (document.getElementById("topic").value == "") {
        return false;
    }
    if (document.getElementById("name").value == "") {
        return false;
    }
    if (document.getElementById("email").value == "") {
        return false;
    }
    if (document.getElementById("textarea").value == "") {
        return false;
    }
    
    return true;
}