if (document.images){
 client_list_on = new Image();client_list_on.src = "images/buttons/our_clients/client_list_on.gif";
 client_list_off = new Image();client_list_off.src = "images/buttons/our_clients/client_list_off.gif";
 case_studies_on = new Image();case_studies_on.src = "images/buttons/our_clients/case_studies_on.gif";
 case_studies_off = new Image();case_studies_off.src = "images/buttons/our_clients/case_studies_off.gif";
 arrow_on = new Image();arrow_on.src = "images/misc/arrow_660000.gif";
 arrow_off = new Image();arrow_off.src = "images/ip.gif";
 arrow_white = new Image();arrow_white.src = "images/misc/arrow_case_select.gif";
}