var preloaded = false;

function newImage(arg) {
	if (document.images) {
		TheImage = new Image();
		TheImage.src = arg;
		return TheImage;
	}
}

function preloadImages() {
	if (document.images) {
		MenuBar = newImage("images/menubar.gif");

                /* menu items */
		HomeLink = newImage("images/button_home_7.gif");
		HomeLink_Over = newImage("images/button_home_hover_7.gif");  

		GeneralLink = newImage("images/button_general_7.gif");
		GeneralLink_Over = newImage("images/button_general_hover_7.gif");

		ProductsLink = newImage("images/button_products_7.gif");
		ProductsLink_Over = newImage("images/button_products_hover_7.gif");

		ProductsLink = newImage("images/button_fire_7.gif");
		ProductsLink_Over = newImage("images/button_fire_hover_7.gif");

		ContactLink = newImage("images/button_contact_7.gif");
		ContactLink_Over = newImage("images/button_contact_hover_7.gif");

		AboutLink = newImage("images/button_about_7.gif");
		AboutLink_Over = newImage("images/button_about_hover_7.gif");

                /* sub menu items */
                /*    General */
		LPGLink = newImage("images/button_lpg_7.gif");
		LPGLink_Over = newImage("images/button_lpg_hover_7.gif");

		IBCLink = newImage("images/button_ibc_7.gif");
		IBCLink_Over = newImage("images/button_ibc_hover_7.gif");

		MiningLink = newImage("images/button_mining_7.gif");
		MiningLink_Over = newImage("images/button_mining_hover_7.gif");

		PetroleumLink = newImage("images/button_petroleum_7.gif");
		PetroleumLink_Over = newImage("images/button_petroleum_hover_7.gif");

                /*    Products */
		TankerEquipLink = newImage("images/button_tanker_e_7.gif");
		TankerEquipLink_Over = newImage("images/button_tanker_e_hover_7.gif");

		TerminalDepotLink = newImage("images/button_terminal_depot_7.gif");
		TerminalDepotLink_Over = newImage("images/button_terminal_dep_hover_7.gif");

		OverfillProLink = newImage("images/button_overfill_pro_7.gif");
		OverfillProLink_Over = newImage("images/button_overfill_pro_hover_7.gif");

		/* etc... */
		preloaded = true;
	}else{
	}
}

function changeImages() {
	if (document.images && (preloaded == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

function showObject(anObject){
		var theObject;//type object
		theObject = document.getElementById(anObject);
		theObject=theObject.style
		theObject.visibility="visible";
		//alert("showing "+theObject.id);
}

function hideObject(anObject){
		var theObject;//type object
		theObject = document.getElementById(anObject);
		theObject=theObject.style
		theObject.visibility="hidden";
		//alert("hidding "+theObject.id);
}

function hideTankerProductObject(anObject){
	var theObject;//type object
	
	hideObject(anObject);
	
	theObject = document.getElementById(anObject);
	theObject=theObject.style;
	theObject.border="5px solid #000000";
	theObject.background="#000000";
}

function ShowTankerProductObject(anObject){
	var theObject;//type object
	
	showObject(anObject);
	
	theObject = document.getElementById(anObject);
	theObject=theObject.style;
	theObject.border="5px solid #0050b4";
	theObject.background="#5596e7";
}

function hideTankerStuff(){
	hideTankerProductObject('topProducts');
	hideObject('topLine');
	hideTankerProductObject('bottomProducts');
	hideObject('bottomLine');
}

function showTankerTopProducts(){
	hideTankerProductObject('bottomProducts'); 
	hideObject('bottomLine');
	ShowTankerProductObject('topProducts');
	showObject('topLine');
}

function showTankerBottomProducts(){
	hideTankerProductObject('topProducts'); 
	hideObject('topLine');
	ShowTankerProductObject('bottomProducts');
	showObject('bottomLine');
}