function offOn(object){

  var path
  var filename


  path = '';
  filename = object.src;

  for (i = object.src.length - 1; i >= 0; i--){
     if (object.src.substring(i,i + 1)=="/" ||object.src.substring(i,i + 2)=="\\"  ) {

        path = object.src.substring(0,i + 1);
        filename = object.src.substring(i + 1);
        break;
     }
  }
  

  if (filename.substring(0,8) == "menu_on_") {
    object.src = path + "menu_off_" + filename.substring(8);
    return;
  }
  else if (filename.substring(0,9) == "menu_off_") { 
    object.src = path + "menu_on_" + filename.substring(9);
    return;
  }

  if (filename.substring(filename.length - 7,filename.length - 4) == "_on") {
    object.src = path + filename.substring(0, filename.length - 7) + "_Off" + filename.substring(filename.length - 4);
    return;
  }
  else if (filename.substring(filename.length - 8,filename.length - 5) == "_off") {
    object.src = path + filename.substring(0, filename.length - 8) + "_on" + filename.substring(filename.length - 4);
    return;
  }


}