// JavaScript Document

function roll_down(id)  {

  document.getElementById("r_"+id).style.visibility="hidden";
  document.getElementById(id).style.position="relative";
  document.getElementById(id).style.top=0;
}

function roll_up(id)  {
   
   document.getElementById("r_"+id).style.visibility="visible";
   document.getElementById(id).style.top= -99999+"px";
   document.getElementById(id).style.position="absolute";
}