nav1_off = new Image();
nav1_off.src = 'images/nav1_off.gif';
nav1_1_on = new Image();
nav1_1_on.src = 'images/nav1_1_on.gif';
nav1_2_on = new Image();
nav1_2_on.src = 'images/nav1_2_on.gif';
nav1_3_on = new Image();
nav1_3_on.src = 'images/nav1_3_on.gif';
nav1_4_on = new Image();
nav1_4_on.src = 'images/nav1_4_on.gif';
nav1_5_on = new Image();
nav1_5_on.src = 'images/nav1_5_on.gif';
nav1_6_on = new Image();
nav1_6_on.src = 'images/nav1_6_on.gif';

nav2_1_off = new Image();
nav2_1_off.src = 'images/nav2_1_off.gif';
nav2_1_1_on = new Image();
nav2_1_1_on.src = 'images/nav2_1_1_on.gif';
nav2_1_2_on = new Image();
nav2_1_2_on.src = 'images/nav2_1_2_on.gif';
nav2_1_3_on = new Image();
nav2_1_3_on.src = 'images/nav2_1_3_on.gif';
nav2_1_4_on = new Image();
nav2_1_4_on.src = 'images/nav2_1_4_on.gif';

nav2_2_off = new Image();
nav2_2_off.src = 'images/nav2_2_off.gif';
nav2_2_1_on = new Image();
nav2_2_1_on.src = 'images/nav2_2_1_on.gif';
nav2_2_2_on = new Image();
nav2_2_2_on.src = 'images/nav2_2_2_on.gif';
nav2_2_3_on = new Image();
nav2_2_3_on.src = 'images/nav2_2_3_on.gif';

nav2_5_off = new Image();
nav2_5_off.src = 'images/nav2_5_off.gif';
nav2_5_1_on = new Image();
nav2_5_1_on.src = 'images/nav2_5_1_on.gif';
nav2_5_2_on = new Image();
nav2_5_2_on.src = 'images/nav2_5_2_on.gif';
nav2_5_3_on = new Image();
nav2_5_3_on.src = 'images/nav2_5_3_on.gif';