//----pre-caching images
function imageon(imgName){
        if (document.images) {
    document[imgName].src = eval(imgName + 'on.src')
}}

function imageoff(imgName){
        if (document.images) {
    document[imgName].src = eval(imgName + 'off.src')
}}
if (document.images) 
{
// main nav images

sub0on = new Image();
sub0on.src = "images/home_on.gif";
sub0off= new Image();
sub0off.src = "images/home_off.gif";

sub1on = new Image();
sub1on.src = "images/news_on.gif";
sub1off= new Image();
sub1off.src = "images/news_off.gif";

sub2on = new Image();
sub2on.src = "images/careers_on.gif";
sub2off= new Image();
sub2off.src = "images/careers_off.gif";


sub3on = new Image();
sub3on.src = "images/contact_us_on.gif";
sub3off= new Image();
sub3off.src = "images/contact_us_off.gif";

// subnav images

// revenue
sub14off = new Image();
sub14off.src = "images/revenue_enhancement/hospital_claims_audits_off.gif";
sub14on= new Image();
sub14on.src = "images/revenue_enhancement/hospital_claims_audits_on.gif";

sub15off = new Image();
sub15off.src = "images/revenue_enhancement/physician_claims_audits_off.gif";
sub15on =  new Image();
sub15on.src = "images/revenue_enhancement/physician_claims_audits_on.gif";

sub16off = new Image();
sub16off.src = "images/revenue_enhancement/asc_audits_off.gif";
sub16on =  new Image();
sub16on.src = "images/revenue_enhancement/asc_audits_on.gif";

sub17off = new Image();
sub17off.src = "images/revenue_enhancement/network_audits_off.gif";
sub17on =  new Image();
sub17on.src = "images/revenue_enhancement/network_audits_on.gif";

sub18off = new Image();
sub18off.src = "images/revenue_enhancement/contract_modeling_off.gif";
sub18on =  new Image();
sub18on.src = "images/revenue_enhancement/contract_modeling_on.gif";

// visium
sub19off = new Image();
sub19off.src = "images/visium/visium_repricer_off.gif";
sub19on= new Image();
sub19on.src = "images/visium/visium_repricer_on.gif";

sub20off = new Image();
sub20off.src = "images/visium/visium_contract_comp_off.gif";
sub20on =  new Image();
sub20on.src = "images/visium/visium_contract_comp_on.gif";

sub21off = new Image();
sub21off.src = "images/visium/visium_contract_manage_off.gif";
sub21on =  new Image();
sub21on.src = "images/visium/visium_contract_manage_on.gif";

sub22off = new Image();
sub22off.src = "images/visium/visium_contract_model_off.gif";
sub22on =  new Image();
sub22on.src = "images/visium/visium_contract_model_on.gif";

sub23off = new Image();
sub23off.src = "images/visium/visium_knowledge_manage_off.gif";
sub23on =  new Image();
sub23on.src = "images/visium/visium_knowledge_manage_on.gif";

// business
sub24off = new Image();
sub24off.src = "images/business_services/data_warehousing_off.gif";
sub24on= new Image();
sub24on.src = "images/business_services/data_warehousing_on.gif";

sub25off = new Image();
sub25off.src = "images/business_services/decision_support_off.gif";
sub25on =  new Image();
sub25on.src = "images/business_services/decision_support_on.gif";

sub26off = new Image();
sub26off.src = "images/business_services/it_consulting_off.gif";
sub26on =  new Image();
sub26on.src = "images/business_services/it_consulting_on.gif";


// sub menu left

// revenue
sub27on = new Image();
sub27on.src = "images/revenue_enhancement/hospital_claims_audits_on.gif";
sub27off =  new Image();
sub27off.src = "images/revenue_enhancement/hospital_claims_audits_off.gif";

sub28on = new Image();
sub28on.src = "images/revenue_enhancement/physician_claims_audits_on.gif";
sub28off= new Image();
sub28off.src = "images/revenue_enhancement/physician_claims_audits_off.gif";

sub29on = new Image();
sub29on.src = "images/revenue_enhancement/asc_audits_on.gif";
sub29off= new Image();
sub29off.src = "images/revenue_enhancement/asc_audits_off.gif";

sub30on = new Image();
sub30on.src = "images/revenue_enhancement/network_audits_on.gif";
sub30off= new Image();
sub30off.src = "images/revenue_enhancement/network_audits_off.gif";

sub31on = new Image();
sub31on.src = "images/revenue_enhancement/contract_modeling_on.gif";
sub31off= new Image();
sub31off.src = "images/revenue_enhancement/contract_modeling_on.gif";

sub40on = new Image();
sub40on.src = "images/revenue_enhancement/aca_on.gif";
sub40off= new Image();
sub40off.src = "images/revenue_enhancement/aca_on.gif";

// visium
sub32off = new Image();
sub32off.src = "images/visium/visium_repricer_off.gif";
sub32on= new Image();
sub32on.src = "images/visium/visium_repricer_on.gif";

sub33off = new Image();
sub33off.src = "images/visium/visium_contract_comp_off.gif";
sub33on =  new Image();
sub33on.src = "images/visium/visium_contract_comp_on.gif";

sub34off = new Image();
sub34off.src = "images/visium/visium_contract_manage_off.gif";
sub34on =  new Image();
sub34on.src = "images/visium/visium_contract_manage_on.gif";

sub35off = new Image();
sub35off.src = "images/visium/visium_contract_model_off.gif";
sub35on =  new Image();
sub35on.src = "images/visium/visium_contract_model_on.gif";

sub36off = new Image();
sub36off.src = "images/visium/visium_knowledge_manage_on.gif";
sub36on =  new Image();
sub36on.src = "images/visium/visium_knowledge_manage_on.gif";

// visium
sub37off = new Image();
sub37off.src = "images/business_services/data_warehousing_on.gif";
sub37on= new Image();
sub37on.src = "images/business_services/data_warehousing_on.gif";

sub38off = new Image();
sub38off.src = "images/business_services/decision_support_off.gif";
sub38on =  new Image();
sub38on.src = "images/business_services/decision_support_on.gif";

sub39off = new Image();
sub39off.src = "images/business_services/it_consulting_off.gif";
sub39on =  new Image();
sub39on.src = "images/business_services/it_consulting_on.gif";
}
// Submenu Image Rollovers

function subimageon(divName,imgName){
	if (document.images) {
		if (document.getElementById){
			document[imgName].src = eval(imgName + 'on.src');
		} else {
		eval('document.layers.'+divName+'.document["' + imgName + '"].src = ' + imgName + 'on.src');
		}
	}
}

function subimageoff(divName,imgName){
	if (document.images) {
		if (document.getElementById){
			document[imgName].src = eval(imgName + 'off.src');
		} else {
		eval('document.layers.'+divName+'.document["' + imgName + '"].src = ' + imgName + 'off.src');
		}
	}
}





	
<!--Begin Layer Menu-->
num = false
myTimer = ""
mapTimer=""

function showLayer(layerName) {
  if (document.layers) {
  	if (num) {
	    document.layers[num].visibility = "hidden";
	}
    document.layers[layerName].visibility = "visible"
  }
  else if (document.getElementById) {
   	if (num) {
    	document.getElementById(num).style.visibility = "hidden";
    }	
    document.getElementById(layerName).style.visibility = "visible";
  }

  num = layerName
}

function hideLayer() {
  if (num){
	
	if (document.layers) {
    	document.layers[num].visibility = "hidden"
  	}
  	else if (document.getElementById) {
    	document.getElementById(num).style.visibility = "hidden";
  	}
  	
  }
}

// Set & Clear Timers That Keep Track of Rollover Submenus

imgTimer=""

function startTimers(){
	myTimer=setTimeout('hideLayer(num)', 1000);
	imgTimer=setTimeout('imageoff(last)', 1000);
}

function stopTimers(){
	clearTimeout(myTimer);
	clearTimeout(imgTimer);
}



/*	// check the platform - send the correct CSS file
if (navigator.platform == "MacPPC") {
	document.writeln('<LINK HREF="inc/mac.css" REL="styleSheet" TYPE="text/css">')
} else {
	document.writeln('<LINK HREF="inc/pc.css" REL="styleSheet" TYPE="text/css">')
}*/