ns4 = (document.layers)? true:false
ie4 = (document.all)? true:false
	
about_off				= new Image();
about_off.src			= "/images/common/about_off.gif";
about_on				= new Image();
about_on.src			= "/images/common/about_on.gif";

catalog_off				= new Image();
catalog_off.src			= "/images/common/catalog_off.gif";
catalog_on				= new Image();
catalog_on.src			= "/images/common/catalog_on.gif";

contact_off				= new Image();
contact_off.src			= "/images/common/contact_off.gif";
contact_on				= new Image();
contact_on.src			= "/images/common/contact_on.gif";

home_off				= new Image();
home_off.src			= "/images/common/home_off.gif";
home_on					= new Image();
home_on.src				= "/images/common/home_on.gif";

iron_post_off			= new Image();
iron_post_off.src		= "/images/common/iron_post_off.gif";
iron_post_on			= new Image();
iron_post_on.src		= "/images/common/iron_post_on.gif";

resources_off			= new Image();
resources_off.src		= "/images/common/resources_off.gif";
resources_on			= new Image();
resources_on.src		= "/images/common/resources_on.gif";

var currentImg = "";
ns4 = (document.layers)? true:false
ie4 = (document.all)? true:false

function img_act(imgName) 
{
        imgOn = eval(imgName + "_on.src");
        document [imgName].src = imgOn;
}

function img_inact(imgName) 
{
	if(currentImg != imgName)
	{
        imgOff = eval(imgName + "_off.src");
        document [imgName].src = imgOff;
    }
}

function img_sel(imgName)
{
	temp = currentImg;
	currentImg = imgName;
	
	if(temp != "")
		img_inact(temp);
}