window.onload = function() {
	
	// preload tab images for navigation bar
	var img01 = new Image; img01.src="tab_aboutus1.jpg";
	var img02 = new Image; img02.src="tab_aboutus2.jpg";
	var img03 = new Image; img03.src="tab_aboutus_on.jpg";
	var img04 = new Image; img04.src="tab_contact.jpg";
	var img05 = new Image; img05.src="tab_contact_on.jpg";
	var img06 = new Image; img06.src="tab_home1.jpg";
	var img07 = new Image; img07.src="tab_home2.jpg";
	var img08 = new Image; img08.src="tab_home_on.jpg";
	var img09 = new Image; img09.src="tab_testdrive1.jpg";
	var img10 = new Image; img10.src="tab_testdrive2.jpg";
	var img11 = new Image; img11.src="tab_testdrive_on.jpg";
	
}