//---------------------------------- DEFINE ALL MAIN NAVIGATION VARIABLES -------------------------------------------------------

//define dropdowns for main nav
menus[0] = new Array ('lyrMNprofile','BASE','*','','','','');
menus[1] = new Array ('lyrMNourwork','BASE','*','','','','');
menus[2] = new Array ('lyrMNwhatwedo','BASE','*','','','','');

var mainMenu = new Array();	//array holding all menu items (populated in init function)
var mainMenuItems = new Array ('profile','ourwork','whatwedo');	//array holding names of main nav items

var mainMenuImgs = new Array();
mainMenuImgs[0] = new Array ('intro','people');
mainMenuImgs[1] = new Array ('client','portfolio','case_studies');
mainMenuImgs[2] = new Array ('interactive','brand','literature','moving','futurashop');

var mainNavActive = -1; //global var holding active main nav

//---------------------------------- MAIN NAVIGATION CONTROL FUNCTIONS -------------------------------------------------------

var mainNavImgsPreloaded = false;	//preload status of main nav images

//preload main nav images
function preloadMainNavImgs () {
	var nav_path = base_path + 'images/main_nav/layer_nav/';
	var i,n,crntArray
	for (i=0;i<mainMenuImgs.length;i++) {
		crntArray = mainMenuImgs[i];
		for (n=0;n<crntArray.length;n++) {
			eval (mainMenuItems[i] + '_' + crntArray[n] + '_off = new Image();');
			eval (mainMenuItems[i] + '_' + crntArray[n] + '_off.src = "' + nav_path + crntArray[n] + '_off.gif"');
			eval (mainMenuItems[i] + '_' + crntArray[n] + '_on = new Image();');
			eval (mainMenuItems[i] + '_' + crntArray[n] + '_on.src = "' + nav_path + crntArray[n] + '_on.gif"');
		}
	}
	mainNavImgsPreloaded = true;
}

//initialisation function for main navigation
function initMainNav () {
	
	//set main nav bar to bottom of page
	var navBarHeight = (48 + 15); //set height of navigation bar
	var pageMinHeight = 410;
	var pageMinWidth = 780;
	var navBarTop = (window_height > pageMinHeight) ? (window_height - navBarHeight) : (pageMinHeight - navBarHeight);	//calculate top position of nav bar
	var navWidth = (window_width > pageMinWidth) ? (window_width - 35) : (pageMinWidth - 35);
	
	if(document.layers) {
		document.layers.lyrMainNav.top = navBarTop;
		document.layers.lyrMainNav.width = navWidth;
		window.setTimeout('document.layers.lyrMainNav.visibility = "show"',100);
	}
	else if(document.all) {
		document.all.lyrMainNav.style.top = navBarTop;
		document.all.lyrMainNav.style.width = navWidth;
		window.setTimeout('document.all.lyrMainNav.style.visibility = "visible"',100);
	}
	else if(document.getElementById) {
		document.getElementById('lyrMainNav').style.top = navBarTop;
		document.getElementById('lyrMainNav').style.width = navWidth;
		window.setTimeout('document.getElementById("lyrMainNav").style.visibility = "visible"',100);
	}
	
	//set main menu bar button active areas
	//mainMenu[0] = new Array ([left],[right],[top],[bottom]);
	mainMenu[0] = new Array (119,287,navBarTop,(navBarTop + 23));	//profile
	mainMenu[1] = new Array (288,456,navBarTop,(navBarTop + 23));	//ourwork
	mainMenu[2] = new Array (457,625,navBarTop,(navBarTop + 23));	//whatwedo
}


//function to get array position of item from itemname
function getMainNavRef(itemName) {	
	for (var i=0;i<mainMenuItems.length;i++)
		if (itemName == mainMenuItems[i]) return i
}

function mainNavOff() {
	if (mainNavActive > -1) {
		var menu_name = ('lyrMN' + mainMenuItems[mainNavActive]); //get currently active dd
		if (menu_name == current_menu) deactivateMenu(menu_name);	//if currently active dd is open then switch it off
	}
	mainNavActive = -1
}

//function to switch on a pop up menu
function mainNavOn(itemName) {
	
	//window.alert ('x position = ' + mx + ' y position = ' + my);
	mainNavActive = getMainNavRef(itemName);	//set selected nav as active
	//window.alert(mainNavActive);
	
	//set coord of dd relative to current position
	var lyrRef,menu_name,absLeft,absTop,absRight,absBottom,crntLyrHeight,navBarTop;
	menu_name = ('lyrMN' + itemName);
	absLeft = mx-15;
	if (document.layers) {
		lyrRef = eval('document.layers.lyrMN' + itemName);	//get reference to current layer
	
		crntLyrHeight = parseInt(lyrRef.clip.bottom);	//get height of current layer
		navBarTop = parseInt(document.layers.lyrMainNav.top);	//get y coord of nav bar
		
		absTop = (navBarTop - (crntLyrHeight + 10));	//calculate top position of pop up
		absRight = (absLeft + parseInt(lyrRef.clip.right));	//calculate right side of pop up
		absBottom = (absTop + crntLyrHeight); //calculate bottom of pop up
		
		lyrRef.top = absTop;	//set left position of pop up
		lyrRef.left = absLeft;	//set right postion of pop up
		
	}
	else {
		//get reference to current layer
		if (document.all) lyrRef = eval('document.all.lyrMN' + itemName);
		else if (document.getElementById) lyrRef = eval('document.getElementById("lyrMN' + itemName + '")');
		
		crntLyrHeight = parseInt(lyrRef.style.height);	//get height of current layer
		navBarTop = (document.all) ? (parseInt(document.all.lyrMainNav.style.top)) : (parseInt(document.getElementById('lyrMainNav').style.top));	//get y coord of nav bar
		
		absTop = (navBarTop - (crntLyrHeight + 10));	//calculate top position of pop up
		absRight = (absLeft + parseInt(lyrRef.style.width));	//calculate right side of pop up
		absBottom = (absTop + crntLyrHeight); //calculate bottom of pop up
		
		lyrRef.style.top = absTop;	//set left position of pop up
		lyrRef.style.left = absLeft;	//set right postion of pop up
		
	}
	
	//set offsets for dd layer
	var offsetTop = 10;
	var offsetBottom = 50;
	var offsetLeft = 10;
	var offsetRight = 10;
	
	absLeft -= offsetLeft;
	absTop -=  offsetTop;
	absRight += offsetRight;
	absBottom += offsetBottom;
	
	setMenuCoords(menu_name,absLeft,absTop,absRight,absBottom);	//set new coord of menu
	activateMenu(menu_name);	//activate menu
	
}


//function to highlight an menu item image
function menuItemRoll(lyrName,imgName,imgState) {
	if(mainNavImgsPreloaded) {
		if(document.layers)
			eval('document.layers.lyrMN' + lyrName + '.document.images.' + imgName + '.src = ' + lyrName + '_' + imgName + '_' + imgState + '.src');
		else
			eval('document.images.' + imgName + '.src = ' + lyrName + '_' + imgName + '_' + imgState + '.src');
	}
}

//function to swap specified image with specified image path
function imgSwap(imgName, imgPath) {
	if (document.layers) document.lyrMainNav.document.images[imgName].src = imgPath;
	else document.images[imgName].src = imgPath;
}