jQuery.preloadImages = function() {
    for (var i = 0; i < arguments.length; i++) {
        jQuery("<img>").attr("src", arguments[i]);
    }
}

// preload images first (can run before page is fully loaded)
$.preloadImages("/assets/images/home/btnCareers_on.png",
                "/assets/images/home/btnClients_on.png",
                "/assets/images/home/btnContactus_on.png",
                "/assets/images/home/btnDisciplines_on.jpg", 
                "/assets/images/home/btnRegistercv_on.png");
$(
	function() {
	    // set up rollover
	    $("img.rollover").hover(
			function() {
			    this.src = this.src.replace("_off", "_on");
			},
			function() {
			    this.src = this.src.replace("_on", "_off");
			}
		);
			$("input.rollover").hover(
			function() {
			    this.src = this.src.replace("_off", "_on");
			},
			function() {
			    this.src = this.src.replace("_on", "_off");
			}
		);
	}
)