function popup(url) {
venster=window.open(url,'venstertje','toolbar=1,location=0,status=0,menubar=1,'+
'scrollbars=2,resizable=0,width=400,height=670');
}

function resizepop() {
breedte=screen.width/2-400/2;
hoogte=screen.height/2-670/2;
window.moveTo(breedte,hoogte);
window.resizeTo(400,670);
}

function popupvev(url) {
venster=window.open(url,'venstertje2','toolbar=1,location=0,status=0,menubar=1,'+
'scrollbars=2,resizable=0,width=400,height=700');
}