var curImage;

function swapImage(imageId) {
	if(imageId != curImage.id) {
		if(document.getElementById(imageId).src.indexOf('_off') != -1) {
			curImage.src = '/images/' + curImage.id + '_off.gif';
			document.getElementById(imageId).src = '/images/' + imageId + '_on.gif';
		} else {
			curImage.src = '/images/' + curImage.id + '_on.gif';
			document.getElementById(imageId).src = '/images/' + imageId + '_off.gif';
		}
	}
}

function preloadImages() {
	var home_off = new Image();
	home_off.src = '/images/home_off.gif';
	var home_on = new Image();
	home_on.src = '/images/home_on.gif';
	var aboutbcs_off = new Image();
	aboutbcs_off.src = '/images/about-bcs_off.gif';
	var aboutbcs_on = new Image();
	aboutbcs_on.src = '/images/about-bcs_on.gif';
	var products_off = new Image();
	products_off.src = '/images/products_off.gif';
	var products_on = new Image();
	products_on.src = '/images/products_on.gif';
	var support_off = new Image();
	support_off.src = '/images/support_off.gif';
	var support_on = new Image();
	support_on.src = '/images/support_on.gif';
	var services_off = new Image();
	services_off.src = '/images/services_off.gif';
	var services_on = new Image();
	services_on.src = '/images/services_on.gif';
	var partners_off = new Image();
	partners_off.src = '/images/partners_off.gif';
	var partners_on = new Image();
	partners_on.src = '/images/partners_on.gif';
	var contact_off = new Image();
	contact_off.src = '/images/contact_off.gif';
	var contact_on = new Image();
	contact_on.src = '/images/contact_on.gif';

	var header_images = document.getElementById('header').getElementsByTagName('img');
	for(var i = 0; i < header_images.length; i++) {
		if(header_images[i].src.indexOf('_on') != -1) {
			curImage = header_images[i];
			break;
		}
	}
}