// nav images
var farm_tractors_off = new Image();
	farm_tractors_off.src = '/images/farm_tractors_off.gif';
var farm_tractors_on = new Image();
	farm_tractors_on.src = '/images/farm_tractors_on.gif';

var new_implements_off = new Image();
	new_implements_off.src = '/images/new_implements_off.gif';
var new_implements_on = new Image();
	new_implements_on.src = '/images/new_implements_on.gif';
	
var used_implements_off = new Image();
	used_implements_off.src = '/images/used_implements_off.gif';
var used_implements_on = new Image();
	used_implements_on.src = '/images/used_implements_on.gif';
	
var construction_equipment_off = new Image();
	construction_equipment_off.src = '/images/construction_equipment_off.gif';
var construction_equipment_on = new Image();
	construction_equipment_on.src = '/images/construction_equipment_on.gif';

var misc_off = new Image();
	misc_off.src = '/images/misc_off.gif';
var misc_on = new Image();
	misc_on.src = '/images/misc_on.gif';
	
window.onload = function()
{
	// set nav image rollovers..
	document.getElementById("nav_ft").onmouseover = navSwap;
	document.getElementById("nav_ui").onmouseover = navSwap;
	document.getElementById("nav_ni").onmouseover = navSwap;
	document.getElementById("nav_ce").onmouseover = navSwap;
	document.getElementById("nav_m").onmouseover = navSwap;

	document.getElementById("nav_ft").onmouseout = navSwap;
	document.getElementById("nav_ui").onmouseout = navSwap;
	document.getElementById("nav_ni").onmouseout = navSwap;
	document.getElementById("nav_ce").onmouseout = navSwap;
	document.getElementById("nav_m").onmouseout = navSwap;

}
function navSwap()
{
	var name_elements = this.src.split("/");
	name_elements = name_elements[name_elements.length -1];
	name_elements = name_elements.split("_");
	file_name = name_elements[0] + ((name_elements.length > 2) ? '_' + name_elements[1] : '');

	this.src = '/images/' + ((name_elements[name_elements.length -1].indexOf("off") != -1) ? file_name + '_on.gif' : file_name + '_off.gif');
}