function setLinkageGroupOptions(chosen,selbox) 
{
  //var selbox = document.search_marker.opttwo;
 
  selbox.options.length = 0;
  if (chosen == " ") 
  { selbox.options[selbox.options.length] = new Option('First select a species.',' '); 
  }

  if (chosen == "tax_3702") 
  { selbox.options[selbox.options.length] = new Option('1','1');
    selbox.options[selbox.options.length] = new Option('2','2');
    selbox.options[selbox.options.length] = new Option('3','3');
    selbox.options[selbox.options.length] = new Option('4','4');
    selbox.options[selbox.options.length] = new Option('5','5');
  }
  if (chosen == "tax_4081") 
  { selbox.options[selbox.options.length] = new Option('1','1');
    selbox.options[selbox.options.length] = new Option('2','2');
    selbox.options[selbox.options.length] = new Option('3','3');
    selbox.options[selbox.options.length] = new Option('4','4');
    selbox.options[selbox.options.length] = new Option('5','5');
    selbox.options[selbox.options.length] = new Option('6','6');
    selbox.options[selbox.options.length] = new Option('7','7');
    selbox.options[selbox.options.length] = new Option('8','8');
    selbox.options[selbox.options.length] = new Option('9','9');
    selbox.options[selbox.options.length] = new Option('10','10');
    selbox.options[selbox.options.length] = new Option('11','11');
    selbox.options[selbox.options.length] = new Option('12','12');
  }
  if (chosen == "tax_4530") 
  { selbox.options[selbox.options.length] = new Option('1','1');
    selbox.options[selbox.options.length] = new Option('2','2');
    selbox.options[selbox.options.length] = new Option('3','3');
    selbox.options[selbox.options.length] = new Option('4','4');
    selbox.options[selbox.options.length] = new Option('5','5');
    selbox.options[selbox.options.length] = new Option('6','6');
    selbox.options[selbox.options.length] = new Option('7','7');
    selbox.options[selbox.options.length] = new Option('8','8');
    selbox.options[selbox.options.length] = new Option('9','9');
    selbox.options[selbox.options.length] = new Option('10','10');
    selbox.options[selbox.options.length] = new Option('11','11');
    selbox.options[selbox.options.length] = new Option('12','12');
  }
}