function openPopup(source, winwidth, winheight, scrollbars) {

var prefs = 'toolbar=no,status=no,menubar=no,location=no,resizable=no,scrollbars=no,width='+ winwidth +',height='+ winheight +',screenX=150,screenY=150';

if(scrollbars==1) {
prefs = 'toolbar=no,status=no,menubar=no,location=no,resizable=no,scrollbars=yes,width='+ winwidth +',height='+ winheight +',screenX=150,screenY=150';
}

win = window.open(source,'OrderReference',prefs);
win.moveTo((screen.width-winwidth)/2,(screen.height-winheight)/2);
win.focus();
}