function swapImageById( image_id ) {
	if( document.getElementById ) {
		var img_elm = document.getElementById( image_id );
		var img_src = img_elm.getAttribute( 'src' );
				
		switch(img_src)
		{
			case "/images/nav/home_out.gif":
				img_elm.setAttribute('src', '/images/nav/home_over.gif');
				break;
			case "/images/nav/home_over.gif":
				img_elm.setAttribute('src', '/images/nav/home_out.gif');
				break;
				
			case "/images/nav/about_us_out.gif":
				img_elm.setAttribute('src', '/images/nav/about_us_over.gif');
				break;
			case "/images/nav/about_us_over.gif":
				img_elm.setAttribute('src', '/images/nav/about_us_out.gif');
				break;
			case "/images/nav/services_out.gif":
				img_elm.setAttribute('src', '/images/nav/services_over.gif');
				break;
			case "/images/nav/services_over.gif":
				img_elm.setAttribute('src', '/images/nav/services_out.gif');
				break;
			case "/images/nav/gallery_out.gif":
				img_elm.setAttribute('src', '/images/nav/gallery_over.gif');
				break;
			case "/images/nav/gallery_over.gif":
				img_elm.setAttribute('src', '/images/nav/gallery_out.gif');
				break;
			case "/images/nav/design_out.gif":
				img_elm.setAttribute('src', '/images/nav/design_over.gif');
				break;
			case "/images/nav/design_over.gif":
				img_elm.setAttribute('src', '/images/nav/design_out.gif');
				break;
			case "/images/nav/fabrication_out.gif":
				img_elm.setAttribute('src', '/images/nav/fabrication_over.gif');
				break;
			case "/images/nav/fabrication_over.gif":
				img_elm.setAttribute('src', '/images/nav/fabrication_out.gif');
				break;
			case "/images/nav/installation_out.gif":
				img_elm.setAttribute('src', '/images/nav/installation_over.gif');
				break;
			case "/images/nav/installation_over.gif":
				img_elm.setAttribute('src', '/images/nav/installation_out.gif');
				break;
			case "/images/nav/links_out.gif":
				img_elm.setAttribute('src', '/images/nav/links_over.gif');
				break;
			case "/images/nav/links_over.gif":
				img_elm.setAttribute('src', '/images/nav/links_out.gif');
				break;
			case "/images/nav/testimonials_out.gif":
				img_elm.setAttribute('src', '/images/nav/testimonials_over.gif');
				break;
			case "/images/nav/testimonials_over.gif":
				img_elm.setAttribute('src', '/images/nav/testimonials_out.gif');
				break;
			case "/images/nav/contact_us_out.gif":
				img_elm.setAttribute('src', '/images/nav/contact_us_over.gif');
				break;
			case "/images/nav/contact_us_over.gif":
				img_elm.setAttribute('src', '/images/nav/contact_us_out.gif');
				break;
			case "/images/nav/back_out.gif":
				img_elm.setAttribute('src', '/images/nav/back_over.gif');
				break;
			case "/images/nav/back_over.gif":
				img_elm.setAttribute('src', '/images/nav/back_out.gif');
				break;
			case "/images/nav/next_out.gif":
				img_elm.setAttribute('src', '/images/nav/next_over.gif');
				break;
			case "/images/nav/next_over.gif":
				img_elm.setAttribute('src', '/images/nav/next_out.gif');
				break;
			case "/images/nav/back_to_top_out.gif":
				img_elm.setAttribute('src', '/images/nav/back_to_top_over.gif');
				break;
			case "/images/nav/back_to_top_over.gif":
				img_elm.setAttribute('src', '/images/nav/back_to_top_out.gif');
				break;
			
			// right side navigation
			case "/images/nav/right/garden_gates_out.gif":
				img_elm.setAttribute('src', '/images/nav/right/garden_gates_over.gif');
				break;
			case "/images/nav/right/garden_gates_over.gif":
				img_elm.setAttribute('src', '/images/nav/right/garden_gates_out.gif');
				break;
			case "/images/nav/right/driveway_gates_out.gif":
				img_elm.setAttribute('src', '/images/nav/right/driveway_gates_over.gif');
				break;
			case "/images/nav/right/driveway_gates_over.gif":
				img_elm.setAttribute('src', '/images/nav/right/driveway_gates_out.gif');
				break;
			case "/images/nav/right/garage_barn_doors_out.gif":
				img_elm.setAttribute('src', '/images/nav/right/garage_barn_doors_over.gif');
				break;
			case "/images/nav/right/garage_barn_doors_over.gif":
				img_elm.setAttribute('src', '/images/nav/right/garage_barn_doors_out.gif');
				break;
			case "/images/nav/right/arbors_trellises_pergolas_out.gif":
				img_elm.setAttribute('src', '/images/nav/right/arbors_trellises_pergolas_over.gif');
				break;
			case "/images/nav/right/arbors_trellises_pergolas_over.gif":
				img_elm.setAttribute('src', '/images/nav/right/arbors_trellises_pergolas_out.gif');
				break;
			case "/images/nav/right/columns_out.gif":
				img_elm.setAttribute('src', '/images/nav/right/columns_over.gif');
				break;
			case "/images/nav/right/columns_over.gif":
				img_elm.setAttribute('src', '/images/nav/right/columns_out.gif');
				break;
				
		}
	}
}