/*

version: 2006-07-01
modification: initial
author: Tim Broddin

*/

enable_page_center = true;

function page_center(id) {
   var page_div = document.getElementById(id);
   
   if (enable_page_center == true) {
      var viewport_height = document.body.clientHeight;
      var viewport_width = document.body.clientWidth;
      
      var position_x = ((viewport_width - page_div.clientWidth) / 2);
      var position_y = ((viewport_height - page_div.clientHeight) / 2);
      
      if (position_x < 0) position_x = 0;
      if (position_y < 0) position_y = 0;
      
      page_div.style.left = position_x + 'px';
   } else {
      page_div.style.left = '0px';
   }

     page_div.style.visibility = 'visible';
}