function win(url,awidth,aheight,wnd,no_scroll) {
	var scroll = (no_scroll) ? 'no':'yes';
	var x=(self.screen.width-awidth)/2; if (x<0) x=0;
	var y=(self.screen.height-aheight)/2; if (y<0) y=0;
	window.open(url,wnd,"width=" + awidth + ", height=" + aheight + ", replace=no, scrollbars=" + scroll + ", resize=no, left="+ x +", top=" + y);
}