function PNGswap(myID, sourceOne, sourceTwo)
{
   var oSpan = document.getElementById(myID)
   var currentAlphaImg = oSpan.filters(0).src
   if (currentAlphaImg.indexOf(sourceOne) != -1)
   {
      oSpan.filters(0).src = currentAlphaImg.replace(sourceOne, sourceTwo)
      }
   else
      oSpan.filters(0).src = currentAlphaImg.replace(sourceTwo, sourceOne)
}

function imgSwap(myID, sourceOne, sourceTwo)
{
   var oImg = document.getElementById(myID)
   var strImg = oImg.src
   if (strImg.indexOf(sourceOne) != -1) 
      oImg.src = strImg.replace(sourceOne, sourceTwo)
   else
      oImg.src = strImg.replace(sourceTwo, sourceOne)
}