function popup(bestand) {
	var win;
	var options = "";
	if (is.nav)
		options = "dependend,"
	win = window.open(bestand, "uitleg" , options + "menubar=no,scrollbars=no,height=300,width=600,left=100,top=100");
	win.focus();
}

function commonPopup(bestand, width, height, moreOptions) {
	var win;
	var options = "";
	if (is.nav)
		options = "dependend,"
	options += "menubar=no,scrollbars=no,height=" + height + ",width=" + width
	if (moreOptions.length > 0)
		options += "," + moreOptions
	win = window.open(bestand, "uitleg" , options);
	win.focus();
}