function popup( url, name, width, height )
	{
    var scroll = 'yes';
	  if( width == 0 )
		  width = screen.width ? screen.width * 9 / 10 : 600;
	  if( height == 0 )
		  height = screen.height ? screen.height * 8 / 10 : 400;
		var left = ( screen.width - width ) / 2;
	  var top = ( screen.height - height ) / 3;
		var attrib = 'width=' + width + ',height=' + height + ',top=' + top + ',left=' + left + ',status=no,scrollbars=' + scroll + ',toolbar=no,menubar=no,status=yes,resizable=yes';
		window.open( url, name, attrib );
	}