function preLoad()
{
	if(document.images)
	 {
		b_about_on = new Image();
		b_about_on.src = 'images/b_about_on.png';
		b_about_off = new Image();
		b_about_off.src = 'images/b_about_off.png';
		b_catalog_on = new Image();
		b_catalog_on.src = 'images/b_catalog_on.png';
		b_catalog_off = new Image();
		b_catalog_off.src = 'images/b_catalog_off.png';
		b_special_on = new Image();
		b_special_on.src = 'images/b_special_on.png';
		b_special_off = new Image();
		b_special_off.src = 'images/b_special_off.png';
		b_contacts_on = new Image();
		b_contacts_on.src = 'images/b_contacts_on.png';
		b_contacts_off = new Image();
		b_contacts_off.src = 'images/b_contacts_off.png';
	}
}

function rollOver(iName, iState)
{
if(document.images)
	{    
	document.images[iName].src = self[iName + '_' + iState].src;
	}
}