function open_window(width, height, file,url, title){
	 var window_width=width;
	 var window_height=height;
         var window_left = (screen.availWidth / 2) - (window_width / 2)
	 var window_top = (screen.availHeight / 2) - (window_height / 2)
         var window_dimensions = 'scrollbars,resizable,' + "height=" + window_height + ",width=" + window_width + ",left="+ window_left + ",top=" + window_top;
	 var htm_file = url + '/' + file; 
	 window.open(url, "", window_dimensions);
	      self.name = title;
      }