function createCookie(sName,oValue,iDays) 
{
  var sExpires;
  if(iDays) 
  {
    var oDate = new Date();
    oDate.setTime(oDate.getTime()+(iDays*24*60*60*1000));
    sExpires = "; expires="+oDate.toGMTString();
  }
  else 
  {
    sExpires = "";
  }
  document.cookie = sName+"="+oValue+sExpires+"; path=/";
}

function readCookie(sName) 
{
  var sNameEQ = sName + "=";
  var sSplitted = document.cookie.split(';');
  var sTemp;
  for(var i=0;i < sSplitted.length;i++) 
  {
    sTemp = sSplitted[i];
    while (sTemp.charAt(0)==' ') 
      sTemp = sTemp.substring(1,sTemp.length);
    if (sTemp.indexOf(sNameEQ) == 0) 
      return sTemp.substring(sNameEQ.length,sTemp.length);
  }
  return null;
}

function eraseCookie(sName) 
{
  createCookie(sName,"",-1);
}