var fenster = null;

function popup(link,name,h,b) {

	top_position = (screen.height) ? (screen.height-h)/2 : 0;

	left_position = (screen.width) ? (screen.width-b)/2 : 0;

	settings = 'toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=yes, width='+b+', height='+h+', top='+top_position+', left='+left_position+', fullscreen=no'

	fenster = window.open(link,name,settings)

}