var img_solarheating_o = new Image();
var img_heatpumps_o = new Image();
var img_grants_o = new Image();
var img_faq_o = new Image();
var img_contactus_o = new Image();

var img_solarheating_n = new Image();
var img_heatpumps_n = new Image();
var img_grants_n = new Image();
var img_faq_n = new Image();
var img_contactus_n = new Image();

img_solarheating_o.src = '/images/menu_solarheating_o.gif';
img_heatpumps_o.src = '/images/menu_heatpumps_o.gif';
img_grants_o.src = '/images/menu_grants_o.gif';
img_faq_o.src = '/images/menu_faq_o.gif';
img_contactus_o.src = '/images/menu_contactus_o.gif';

img_solarheating_n.src = '/images/menu_solarheating.gif';
img_heatpumps_n.src = '/images/menu_heatpumps.gif';
img_grants_n.src = '/images/menu_grants.gif';
img_faq_n.src = '/images/menu_faq.gif';
img_contactus_n.src = '/images/menu_contactus.gif';

function swap_image(menu_option,over)
{
	if(document.getElementById('img_' + menu_option))
	{
		if(over == 'over')
		{
			document.getElementById('img_' + menu_option).src = eval('img_' + menu_option + '_o').src;	
		}
		else
		{
			document.getElementById('img_' + menu_option).src = eval('img_' + menu_option + '_n').src;	
		}
	}
}