var window_top_arch=((screen.availHeight-500)/2)-20;
var window_left_arch=((screen.availWidth-700)/2);
var window_top;
var window_left;

function window_open(page,name,width,height){
	window_left=eval("(screen.availWidth-"+width+")/2-15");
	window_top=eval("(screen.availHeight-"+height+")/2-20");
	window.open(page,name,'width='+width+',height='+height+',top='+window_top+',left='+window_left+',toolbar=1,resizable=1,scrollbars=1');
}