var NS4DOM = (document.layers) ? true:false;
var IEDOM = (document.all) ? true:false;
var W3CDOM = (document.getElementById) ? true:false;

function getObject(id) {
   if (NS4DOM) ref="document."+id;
   else if (IEDOM) ref=id;
   else if (W3CDOM) ref="document.getElementById('"+id+"')";
   var object=eval(ref);
   return object;
}

function hideIt(id) {
   if (NS4DOM) getObject(id).visibility="hide";
   else if (IEDOM || W3CDOM) getObject(id).style.visibility="hidden";
}

function showIt(id) {
   if (NS4DOM) getObject(id).visibility="show";
   else if (IEDOM || W3CDOM) getObject(id).style.visibility="visible";
}