function set_navitrenner()
{
	var elements = document.getElementsByTagName( "td" );
	var array = new Array(2);
   
	for( i=0; i < elements.length; i++ )
	{
		var tag = elements[i];
		if ( tag.className == "navitrenner" )
		{
			array[i%2] = tag;
		}
	}
  
	array[0].style.visibility = "hidden";
	array[1].style.visibility = "hidden";
}