var bJava = ( document.images );
if ( bJava )

{

classesOff = new Image();
classesOff.src = "images/nav_classes.gif";

classesOn = new Image();
classesOn.src = "images/nav_classes_on.gif";

lecturesOff = new Image();
lecturesOff.src = "images/nav_lectures.gif";

lecturesOn = new Image();
lecturesOn.src = "images/nav_lectures_on.gif";

publicationsOff = new Image();
publicationsOff.src = "images/nav_publications.gif";

publicationsOn = new Image();
publicationsOn.src = "images/nav_publications_on.gif";


aboutOff = new Image();
aboutOff.src = "images/nav_about.gif";

aboutOn = new Image();
aboutOn.src = "images/nav_about_on.gif";

reflectionsOff = new Image();
reflectionsOff.src = "images/nav_reflections.gif";

reflectionsOn = new Image();
reflectionsOn.src = "images/nav_reflections_on.gif";


}

function On( imgName) 
{
	if ( bJava )
	{
		img = eval( imgName + "On.src");
		document[imgName].src = img;  
	}
}
function Off( imgName) 
{
	if ( bJava )

	{
		img = eval( imgName + "Off.src");
		document[imgName].src = img; 
	}
}