if (document.images) {
 img1 = new Image();
 img1.src = 'images/mainnav_home_on.gif';
 img2 = new Image();
 img2.src = 'images/mainnav_aboutus_on.gif';
 img3 = new Image();
 img3.src = 'images/mainnav_lessons_on.gif';
 img4 = new Image();
 img4.src = 'images/mainnav_repairs_on.gif';
 img5 = new Image();
 img5.src = 'images/mainnav_locations_on.gif';
 img6 = new Image();
 img6.src = 'images/btn_electric_guitar_on.gif';
 img7 = new Image();
 img7.src = 'images/btn_acoustic_guitar_on.gif';
 img8 = new Image();
 img8.src = 'images/btn_guitar_amps_on.gif';
 img9 = new Image();
 img9.src = 'images/btn_bass_guitar_on.gif';
 img10 = new Image();
 img10.src = 'images/btn_pedals_on.gif';
 img11 = new Image();
 img11.src = 'images/btn_pa_off_on.gif';
 img12 = new Image();
 img12.src = 'images/btn_recording_on.gif';
 img13 = new Image();
 img13.src = 'images/btn_accessories_on.gif';
}