function addLoadEvent(func) {
	var oldonload = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	}
	else {
		window.onload = function() {
			oldonload();
			func();
		}
	}
}

function preLoadImages() {
	imgp1 = new Image();
	imgp2 = new Image();
	imgp3 = new Image();
	imgp4 = new Image();
	
    imgp1.src = "/images/about-us/community-involvement/habitat-large-1.jpg";
    imgp2.src = "/images/about-us/community-involvement/habitat-large-2.jpg";
    imgp3.src = "/images/about-us/community-involvement/habitat-large-3.jpg";
    imgp4.src = "/images/about-us/community-involvement/habitat-large-4.jpg";
}

function img_switch (id) {
	var habitat = document.getElementById("habitat");
	
	habitat_src = "/images/about-us/community-involvement/habitat-large-" + id + ".jpg";
	
	habitat.setAttribute("src",habitat_src);
	
	return false;
}

addLoadEvent(preLoadImages);