if (document.images) {
	// Preload Main Navigation
	subnav1a=new Image; subnav1a.src="images/n_degree_residential_1.gif";
	subnav1b=new Image; subnav1b.src="images/n_degree_residential_2.gif";

	subnav2a=new Image; subnav2a.src="images/n_degree_external_1.gif";
	subnav2b=new Image; subnav2b.src="images/n_degree_external_2.gif";
	
	subnav3a=new Image; subnav3a.src="images/n_degree_correspondance_1.gif";
	subnav3b=new Image; subnav3b.src="images/n_degree_correspondance_2.gif";
	
	subnav4a=new Image; subnav4a.src="images/n_degree_modular_1.gif";
	subnav4b=new Image; subnav4b.src="images/n_degree_modular_2.gif";
	
	subnav5a=new Image; subnav5a.src="images/n_degree_descriptions_1.gif";
	subnav5b=new Image; subnav5b.src="images/n_degree_descriptions_2.gif";
	
	subnav6a=new Image; subnav6a.src="images/n_degree_degrees_1.gif";
	subnav6b=new Image; subnav6b.src="images/n_degree_degrees_2.gif";
}