function new_window(url,w,h){
	var s_w=screen.availWidth;
	var s_h=screen.availHeight;
	
	if (w>s_w) w=s_w
	if (h>s_h-50) h=s_h-50
	
	w=w*1+17;
	h=h*1+4;
	w_left=(s_w-w)/2
	w_top=(s_h-h)/2
	
	
	window_size="scrollbars=1, resizable=1, height="+h+",width="+w+",left="+w_left+",top="+w_top
	nw = window.open(url,"nw",window_size)
	nw.focus()
}