//PRELOAD ROLLOVER IMAGES 
<!--
if (document.images) {
	preload1= new Image; 
	preload1.src="/img/menu-AirSupported_RO.jpg"; 
	preload2= new Image; 
	preload2.src="/img/menu-CustDesigTension_RO.jpg"; 
	preload3= new Image; 
	preload3.src="/img/menu-PreEngTension_RO.jpg";
	preload4= new Image; 
	preload4.src="/img/menu-TentStruc_RO.jpg";  
}
//-->

//ARRAY TO HOLD CATEGORIES
var arrCategories=new Array(4);
arrCategories[0]="AirSupported";
arrCategories[1]="CustDesigTension";
arrCategories[2]="PreEngTension";
arrCategories[3]="TentStruc";


//OPEN MENU FUNCTION
function openMenu(targetDIV) {
	var targetHDR = targetDIV.id;
	
	//CHECK IF MENU IS ALREADY OPEN
	//var strSearch = document["img_" + targetHDR].src;
	//alert(document.getElementById("img_" + targetHDR).src);
	var strSearch = document.getElementById("img_" + targetHDR).src;
	
	//alert (strSearch + "\n\n" + strSearch.indexOf("_RO.jpg"));
	if (strSearch.indexOf("_RO.jpg")!=-1) {
		//SELECTED MENU IS ALREADY OPEN - CLOSE ALL OPEN MENUS
		//CHANGE ALL CATEGORY HDRS TO "CLOSED" AND CLOSE ALL MENUS
		 var x=0;
		 for (x=0; x<arrCategories.length; x++) {
			document.getElementById("img_" + arrCategories[x]).src="/img/menu-" + arrCategories[x] + ".jpg";
			closeMenu(document.getElementById(arrCategories[x]));
		 } 			 
	} else {	
		//SELECTED CATEGORY WAS NOT OPEN...
		//CHANGE ALL CATEGORY HDRS TO "CLOSED" AND CLOSE ALL MENUS
		var x=0;
		for (x=0; x<arrCategories.length; x++) {
			document.getElementById("img_" + arrCategories[x]).src="/img/menu-" + arrCategories[x] + ".jpg";
			closeMenu(document.getElementById(arrCategories[x]));
		 } 		
		 
		//OPEN SELECTED CATEGORY (change DIV style to open which contains "display: visible")
		targetDIV.className="menuOpen";
		//CHANGE SELECTED CATEGORY HDR TO "OPEN"
		document.getElementById("img_" + targetHDR).src="/img/menu-" + targetHDR + "_RO.jpg";
	}
}

//CLOSE MENU FUNCTION
function closeMenu(targetDIV) {
	targetDIV.className="menuClosed";
}