function ChangeDisplay(id)
    {
     //obj = document.getElementById(id_); 
     var divs = new Array();
     divs[0] = "productoverview";
     divs[1] = "productspecifications";
     divs[2] = "productdownloads";
     
     for (var i = 0; i < divs.length; i++)
     {
         if (id != divs[i] )
         {
             document.getElementById(divs[i]).style.display="none";
             document.getElementById(divs[i]+'_link').className = "link_product_detail";
         }
     }
     document.getElementById(id).style.display="block";
     document.getElementById(id+'_link').className = "link_product_detail active_product_detail";
}