//	Grab the list items in the main navigation list and run hide or show functions as appropriate.
function drop_down() 
{
	//	Make sure browser is capable to doing the things we need.
	if(!document.getElementsByTagName) return false;
	if(!document.getElementById) return false;
	
	//	Do the class changes as appropriate.
	var list_items = document.getElementById("main_navigation").getElementsByTagName("li");
	var i = 0;
	while (i < list_items.length) 
	{
		list_items[i].onmouseover=function() 
		{
			this.className+=" drop_down";
		}
		list_items[i].onmouseout=function() 
		{
			this.className=this.className.replace(new RegExp(" drop_down\\b"), ""); 
		}
		
		i++;
	}
}

/*** Switch out banner elements based on hovered menu element ***/

function switcher()
{
if (document.getElementById("secondary_navigation")) {
	var secondary_navigation = document.getElementById("secondary_navigation");
	var banner = document.getElementById("banner");
	
	var body_tag = document.getElementsByTagName("body");
	var body_id = body_tag[0].id;
	var home_id = body_id.substring(2) + '_banner';
	var home_banner = document.getElementById(home_id);
	var nav_items = secondary_navigation.getElementsByTagName("li");
	var i = 0;
	
	while(i < nav_items.length)
	{
		nav_items[i].onmouseover = function() 
		{
			home_banner.style.display = 'none';
			var id_name = this.className + "_banner";
			document.getElementById(id_name).style.position = 'relative';
			document.getElementById(id_name).style.left = '0';
			document.getElementById(id_name).style.display = 'block';
		}
		
		nav_items[i].onmouseout = function() 
		{
			var id_name = this.className + "_banner";
			document.getElementById(id_name).style.display = 'none';
			home_banner.style.display = 'block';
		}
		
		i++;
	}
    }
}

function addOnload(newFunction) {
  var oldOnload = window.onload;
    // does window.onload exist
  if (typeof oldOnload == "function") {
            //overwriting existing onload
              window.onload = function() {
                  if (oldOnload) {oldOnload();}
                  newFunction();
              }
          }
          else {
              window.onload = newFunction;
          }
} 


addOnload(drop_down);
addOnload(switcher);

/***This one makes image captions from the alt tags***/

function addCaption( oImgElem, bUseCaptionMarker )
{
  // Insert Caption
  var oCaptionElem = document.createElement("div");
  oCaptionElem.className = "caption";

  var oCaptionTextElem = document.createElement("div");
  oCaptionTextElem.className = "caption-text";
  var oCaptionText = document.createTextNode( oImgElem.alt );
  oCaptionTextElem.appendChild(oCaptionText );
  oCaptionElem.appendChild(oCaptionTextElem);

  if(oImgElem.nextSibling) 
    oImgElem.parentNode.insertBefore(oCaptionElem,
      oImgElem.nextSibling);
  else
    oImgElem.parentNode.appendChild(oCaptionElem);

  with(oImgElem.style)
  {
    oCaptionElem.style.width = (oImgElem.width+borderLeft+
      borderRight+paddingLeft+paddingRight)+"px";
  }

  return true; 
}

/*
	Standards Compliant Rollover Script
	Author : Daniel Nolan
	http://www.bleedingego.co.uk/webdev.php
	
	Add the attribute class="imgover" to any image in your document that requires a mouseover effect to be trigger
        Hover image is named exactly the same as the original image plus _o at the end of name
*/

function initRollovers() {

	if (!document.getElementById) return
	
	var aPreLoad = new Array();
	var sTempSrc;
	var aImages = document.getElementsByTagName('img');

	for (var i = 0; i < aImages.length; i++) {		
	
		//there may be multiple class assignments
		//separates the img class into an array
		classes = aImages[i].className.split(" ");
				
		//checks if img has a class of menu
		//if so, set up rollover
		if ( inArray('imgover', classes) ) {

			var src = aImages[i].getAttribute('src');
			var ftype = src.substring(src.lastIndexOf('.'), src.length);
			var hsrc = src.replace(ftype, '_o'+ftype);

			aImages[i].setAttribute('hsrc', hsrc);
			
			aPreLoad[i] = new Image();
			aPreLoad[i].src = hsrc;
			
			aImages[i].onmouseover = function() {
				sTempSrc = this.getAttribute('src');
				this.setAttribute('src', this.getAttribute('hsrc'));
			}	
			
			aImages[i].onmouseout = function() {
				if (!sTempSrc) sTempSrc = this.getAttribute('src').replace('_o'+ftype, ftype);
				this.setAttribute('src', sTempSrc);
			}

		}
	}
}

function inArray( value, array ) {
//passed a value and an array, this function returns true
//if the value is contained with in the array,
//false if it is not

	for ( var i = 0; i < array.length; i++ )
		if ( array[i] == value )
			return true;
	return false;


} 

//adds functions to the windows onload event
function addOnload(newFunction) {
  var oldOnload = window.onload;
    // does window.onload exist
  if (typeof oldOnload == "function") {
            //overwriting existing onload
              window.onload = function() {
                  if (oldOnload) {oldOnload();}
                  newFunction();
              }
          }
          else {
              window.onload = newFunction;
          }
} 

addOnload(initRollovers);