/*
 * nvHover
 * Navigation swap function
 */
function nvHover(id,option) 
{
  if(option==1) {
    var rep=document.getElementById(id).attributes.src.value;
    cut=rep.replace("0","1");
    document.getElementById(id).src=cut;
  }
  else {
  var rep=document.getElementById(id).attributes.src.value;
  cut=rep.replace("1","0");
  document.getElementById(id).src=cut;
 }
}