function opnewWin(s, w, h, is_centered, pars)
{  
 var winank;
 if (is_centered == 1)
 {
  var coord = new Array();
  coord = get_center_window_coord(h, w);
  left_pos = coord["x"];
  top_pos = coord["y"];
  winank = window.open(s, "popup", "height=" + h + ",width=" + w + ",,,,,,top=" + top_pos + ",left=" + left_pos + pars);
 }
 else
 {
  winank = window.open(s, "popup", "width= " + w + ", height= " + h + pars);
 }  
}

function get_center_window_coord(h_desc, w_desc)
{
 var coord = new Array("x", "y");
 var swidth=0;
 var sheight=0;
 var left_pos, top_pos;
 h_desc = h_desc || 500;
 w_desc = w_desc || 600;
 if (self.screen) { // for NN4 and IE4
   swidth = screen.width;
   sheight = screen.height   
 } else if (self.java) { // for NN3 with enabled Java
   var jkit = java.awt.Toolkit.getDefaultToolkit();
   var scrsize = jkit.getScreenSize();
   swidth = scrsize.width;
   sheight = scrsize.height;
 }
 coord["x"] = (swidth/2) - (w_desc/2);
 coord["y"] = (sheight/2) - (h_desc/2);
 return coord;
}