var imageFiles_a_21 = new Array();
imageFiles_a_21['0'] = new Array ('_images/a_Home.gif', '_images/a_HomeMouseover.gif');
imageFiles_a_21['1'] = new Array ('_images/a_About_Us.gif', '_images/a_About_UsMouseover.gif');
imageFiles_a_21['2'] = new Array ('_images/a_Services.gif', '_images/a_ServicesMouseover.gif');
imageFiles_a_21['3'] = new Array ('_images/a_Insulation.gif', '_images/a_InsulationMouseover.gif');
imageFiles_a_21['4'] = new Array ('_images/a_Duct_Cleaning.gif', '_images/a_Duct_CleaningMouseover.gif');
imageFiles_a_21['5'] = new Array ('_images/a_Leaky_Ducts.gif', '_images/a_Leaky_DuctsMouseover.gif');
imageFiles_a_21['6'] = new Array ('_images/a_Dryer_Ducts.gif', '_images/a_Dryer_DuctsMouseover.gif');
imageFiles_a_21['7'] = new Array ('_images/a_FAQs.gif', '_images/a_FAQsMouseover.gif');
imageFiles_a_21['8'] = new Array ('_images/a_Contact_Us.gif', '_images/a_Contact_UsMouseover.gif');
imageFiles_a_21['9'] = new Array ('_images/a_Request_Form.gif', '_images/a_Request_FormMouseover.gif');
imageFiles_a_21['10'] = new Array ('_images/a_Links.gif', '_images/a_LinksMouseover.gif');
imageFiles_a_21['11'] = new Array ('_images/a_Site_Map.gif', '_images/a_Site_MapMouseover.gif');
imageFiles_a_21['12'] = new Array ('_images/a_Windows.gif', '_images/a_WindowsMouseover.gif');

function image_on_a_21 (position) {
   var doc = eval("document.imagea_21" + position);
   doc.src = imageFiles_a_21[position][1];
}

function image_off_a_21 (position) {
   var doc = eval("document.imagea_21" + position);
   doc.src = imageFiles_a_21[position][0];
}