var ns6 = false;
var ns4 = (document.layers)? true:false;
var ie4 = (document.all)? true:false;
var opera = (window.opera)? true:false;		//for opera, "ie4" and "opera" are true
if (ns4 == ie4 && opera == false) {			//if the DOM is none of the above, it must be NS6
	ns6 = true;
	ie4 = ns4 = false;
}
var dropNavAltImg = new Image();
dropNavAltImg.src = "/media/images/dropnav-arr-over.gif";
var dropNavOrigImg = new Image();
dropNavOrigImg.src = "/media/images/spacer.gif";
var dropNavRightImgOff = new Image();
dropNavRightImgOff.src = "/media/images/dropnav-right.gif";
var dropNavRightImgOver = new Image();
dropNavRightImgOver.src = "/media/images/dropnav-right-over.gif";
var dropNavBottomRightImgOff = new Image();
dropNavBottomRightImgOff.src = "/media/images/dropnav-right-bot.gif";
var dropNavBottomRightImgOver = new Image();
dropNavBottomRightImgOver.src = "/media/images/dropnav-right-bot-over.gif";
var dropNavPhotosOff = new Array();
var dropNavPhotosOn = new Array();
var indAbbr = ["ra","jia","psa","as","pso"];
for (var i = 0; i < indAbbr.length; i++){
	dropNavPhotosOff[i] = new Image();
	dropNavPhotosOn[i] = new Image();
	dropNavPhotosOff[i].src = "/media/images/dropnav-img-" + indAbbr[i] + ".gif";
	dropNavPhotosOn[i].src = "/media/images/dropnav-img-" + indAbbr[i] + "-on.gif";
}
dropNavPhotosOff[4].src = "/psoriasis/media/images/dropnav-img-eie.gif";
dropNavPhotosOn[4].src = "/psoriasis/media/images/dropnav-img-eie-on.gif";


//initialize objects
function object_init(name) {
	if (ie4) return eval(name+'.style');
	if (ns6) return eval('document.getElementById("'+name+'").style');
}

//switch object visibility to visible
function show_object(obj) {
	obj.visibility = 'visible';
}

//switch object visibility to hidden
function hide_object(obj) {
	obj.visibility = 'hidden';
}

//switch object visibility to inherit
function inherit_object(obj) {
	obj.visibility = 'inherit';
}

//move object to a certain coordinate
function move_to(obj,x,y) {
	obj.left = x;
	obj.top = y;
}

//clip object - needs object reference
function clip_object(obj,xmin,ymin,xmax,ymax) {
	obj.clip = 'rect(' + ymin + 'px ' + xmax + 'px ' + ymax + 'px ' + xmin + 'px)';
}


//return the height of the layer in pixels - needs layer name
function layer_height(lay) {
	if(ie4 && !opera) return eval(lay+'.clientHeight');
	if(ns6) return eval('document.getElementById("'+lay+'").offsetHeight');
	if(opera) return eval(lay+'.style.pixelHeight');
}

//return the width of the layer in pixels - needs layer name
function layer_width(lay) {
	if(ie4 && !opera) return eval(lay+'.clientWidth');
	if(ns6) return eval('document.getElementById("'+lay+'").offsetWidth');
	if(opera) return eval(lay+'.style.pixelWidth');
}

//find object position by recursively checking parent offsets
function findPosX(obj) {
	var curleft = 0;
	if (obj.offsetParent)
	{
		while (obj.offsetParent)
		{
			curleft += obj.offsetLeft
			obj = obj.offsetParent;
		}
	}
	else if (obj.x)
		curleft += obj.x;
	return curleft;
}


function findPosY(obj) {
	var curtop = 0;
	if (obj.offsetParent)
	{
		while (obj.offsetParent)
		{
			curtop += obj.offsetTop
			obj = obj.offsetParent;
		}
	}
	else if (obj.y)
		curtop += obj.y;
	return curtop;
}


var status_overmenu = -1;
var status_last_overmenu = -1;
var status_waitforclear = false;
var timer_id = -1;

// main navigation rollover functions
function nav_mouseover(nc,dif) {
	if (ie4) {										// browser offset
		boffx = 0;
		boffy = 0;
	} else {
		boffx = 0;	
		boffy = 0;	
	}
	navdropdown = object_init('expandedConditionNav');			// create and place drop down
	move_to(navdropdown,(findPosX(nc)-dif+boffx)+'px',(findPosY(nc)+boffy)+'px');
	eval('show_object(navdropdown)');
	eval('show_object(dropnavcellOverObj)');
	status_overmenu = 1;
	if (status_waitforclear) {						// new rollover has happened while previous onstate has not been cleared yet
		status_waitforclear = false;
	}
}

function nav_mouseoverdropdown() {
	status_overmenu = 1;
	eval('show_object(dropnavcellOverObj)');
	clearTimeout(timer_id);							// stop clear-nav-timer since mouse is now over dropdown
}


function nav_mouseout() {
	status_last_overmenu = status_overmenu;			// keep id of previously rolled-over nav item for eventual clear
	status_overmenu = -1;
	status_waitforclear = true;						// flag: nav is waiting for clear to happen
	timer_id = setTimeout('nav_clear()',500);		// 1/2 sec pause before we commit to clear
}

function nav_clear() {								// called from mouse-out routine via 1/2 sec timer to allow user to correct erroneous mouse movements
	if (status_overmenu == -1) {					// user didn't correct, clear drop downs and on states
		eval('hide_object(navdropdown)');
		eval('hide_object(dropnavcellOverObj)');
	}
	status_waitforclear = false;
}

function swapStyles(elemID,styleClass){
	if (document.getElementById(elemID).className != styleClass) {
		document.getElementById(elemID).className = styleClass;
	}
}