function getXMLHttp() {
	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;
}// JavaScript Document

function MakeRequest(params) {
	var xmlHttp = getXMLHttp();
  	xmlHttp.onreadystatechange = function() {
    	if(xmlHttp.readyState == 4) {
      		HandleResponse(xmlHttp.responseText);
    	}
  	}
	
	xmlHttp.open("POST", "php/mail.php", true); 
	xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	xmlHttp.setRequestHeader("Content-Length", params.length);
  	xmlHttp.send(params);
}

function HandleResponse(response) {
  	alert(response);
	clearFields();
}

function sendMail(){
	var strVelden = "";
	
	var naam = document.getElementById('txtNaam').value;
	var email = document.getElementById('txtEmail').value;
	var bericht = document.getElementById('txtBericht').value;
	
	if(naam == ""){
		strVelden = "  - naam\n";
	}
	if(email == ""){
		strVelden += "  - email\n";		
	}
	if(bericht == ""){
		strVelden += "  - bericht\n";
	}
	
	if(strVelden != ""){
		alert("Gelieve volgende velden in te vullen:\n"	+ strVelden);
	}
	else{
		var params = "naam=" + naam + "&email=" + email + "&bericht=" + bericht;
		MakeRequest(params);
	}
}

function clearFields(){
	document.getElementById('txtNaam').value = "";
	document.getElementById('txtEmail').value = "";
	document.getElementById('txtBericht').value = "";
}