if (document.images) {
  option1_off = new Image(98,28);
  option1_off.src = "/retadv/apps/images/nav/nav_home.gif";
  option1_on = new Image(98,28);
  option1_on.src = "/retadv/apps/images/nav/nav_home_over.gif";

  option2_off = new Image(98,28);
  option2_off.src = "/retadv/apps/images/nav/nav_tools.gif";
  option2_on = new Image(98,28);
  option2_on.src = "/retadv/apps/images/nav/nav_tools_over.gif";

  option3_off = new Image(98,28);
  option3_off.src = "/retadv/apps/images/nav/nav_learning.gif";
  option3_on = new Image(98,28);
  option3_on.src = "/retadv/apps/images/nav/nav_learning_over.gif";

  option4_off = new Image(98,28);
  option4_off.src = "/retadv/apps/images/nav/nav_directory.gif";
  option4_on = new Image(98,28);
  option4_on.src = "/retadv/apps/images/nav/nav_directory_over.gif";

  option5_off = new Image(99,28);
  option5_off.src = "/retadv/apps/images/nav/nav_about.gif";
  option5_on = new Image(99,28);
  option5_on.src = "/retadv/apps/images/nav/nav_about_over.gif";

}

function rollover(imgDocID) {
	var clearImgDocIDs = imgDocID;
    if (document.images) {
		for (var x = 1; x <= 5; x++) {
			var clearImgDocIDs = 'option' + x;
			var clearImgDocIDName = clearImgDocIDs + '_off';
    		document.images[clearImgDocIDs].src = eval(clearImgDocIDName + ".src");
		}
    	document.images[imgDocID].src = eval(imgDocID + "_on.src");
  }
}

function expand(layer_ref) { 
	collapseAll();
//	alert(layer_ref);
	if (document.all) { //IS IE 4 or 5 (or 6 beta) 
		eval( "document.all." + layer_ref + ".style.display = 'block'"); 
	} 
	if (document.layers) { //IS NETSCAPE 4 or below 
		document.layers[layer_ref].display = "block"; 
	} 
	if (document.getElementById &&!document.all) { 
		hza = document.getElementById(layer_ref); 
		hza.style.display = "block"; 
	} 
} 

function collapseAll() { 
	for (var x = 1; x <= 5; x++) {
		var layer_ref = 'option' + x + 'Text';
		if (document.all) { //IS IE 4 or 5 (or 6 beta) 
			eval( "document.all." + layer_ref + ".style.display = 'none'"); 
		} 
		if (document.layers) { //IS NETSCAPE 4 or below 
			document.layers[layer_ref].display = "none"; 
		} 
		if (document.getElementById &&!document.all) { 
			hza = document.getElementById(layer_ref); 
			hza.style.display = "none"; 
		} 
	}
}