function createRequestObject() {
    var ro;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        ro = new ActiveXObject("Microsoft.XMLHTTP");
    }else{
        ro = new XMLHttpRequest();
    }
    return ro;
}

function handleResponse(popup_id) {
 document.getElementById("mypopup_" + popup_id).style.display = "block";
 document.getElementById("antwoord" + popup_id).style.display = "block";
 document.getElementById("contactform" + popup_id).style.display = "none";
}
var http = createRequestObject();

function sendemail(popup_id) {
	var email = document.getElementById('email' + popup_id).value;
	var soort = document.getElementById('soort' + popup_id).value;
	var beschrijving = document.getElementById('beschrijving' + popup_id).value;
	var prijs = document.getElementById('prijs' + popup_id).value;
	var merk = document.getElementById('merk' + popup_id).value;
	document.getElementById('versturen' + popup_id).disabled=true; 
	document.getElementById('versturen' + popup_id).value='Een moment geduld svp....';
	http.open('post', '/mail.php', true);
	http.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	http.send('email='+ encodeURI(email) +'&soort='+soort+'&prijs='+prijs+'&beschrijving='+beschrijving+'&merk='+merk);
    http.onreadystatechange = handleResponse(popup_id);

}

function myPopupRelocate(popup_id) {
 var scrolledX, scrolledY;
 if( self.pageYOffset ) {
   scrolledX = self.pageXOffset;
   scrolledY = self.pageYOffset;
 } else if( document.documentElement && document.documentElement.scrollTop ) {
   scrolledX = document.documentElement.scrollLeft;
   scrolledY = document.documentElement.scrollTop;
 } else if( document.body ) {
   scrolledX = document.body.scrollLeft;
   scrolledY = document.body.scrollTop;
 }

 var centerX, centerY;
 if( self.innerHeight ) {
   centerX = self.innerWidth;
   centerY = self.innerHeight;
 } else if( document.documentElement && document.documentElement.clientHeight ) {
   centerX = document.documentElement.clientWidth;
   centerY = document.documentElement.clientHeight;
 } else if( document.body ) {
   centerX = document.body.clientWidth;
   centerY = document.body.clientHeight;
 }

 var leftOffset = scrolledX + (centerX - 250) / 2;
 var topOffset = scrolledY + (centerY - 200) / 2;

 document.getElementById("mypopup_" + popup_id).style.top = topOffset + "px";
 document.getElementById("mypopup_" + popup_id).style.left = leftOffset + "px";
}

function fireMyPopup(popup_id) {
 myPopupRelocate(popup_id);
 document.getElementById("mypopup_" + popup_id).style.display = "block";
 document.body.onscroll = myPopupRelocate;
 window.onscroll = myPopupRelocate;
}