/*****************************************************************
	Contents Changer Class

	*Properties*
	_layers				Array
	_btnObj				Array
	_this				Object(self)

	*Methods*
	addContents			Add DivObject
	init				First
	change				Contents Change
	setDivVisibility	Private Method

*****************************************************************/

if (typeof ContentsChanger == 'undefined') {
var ContentsChanger = function() {

	/**************
	* Properties
	*/

	var _layers = [];
	var _btnObj = [];
	var _this;


	/**************
	* Methods
	*/

	return {

		/**************
		* addContents
		* 1.div object
		*/

		addContents:	function(div){
			_layers.push(div);
		},

		/**************
		* init
		*/

		init:	function(obj){
			_this = obj;
			var i = _layers.length;
			while(--i>-1){
				if(i>0){
					_layers[i].style.position = "absolute";
					_layers[i].style.zIndex = i+1;
					_this.setDivVisibility(_layers[i], false);
				}else{
					_layers[i].style.position = "relative";
					_this.setDivVisibility(_layers[i], true);
				}
			}
		},

		/**************
		* change
		*/

		change:	function(index){
			var i = _layers.length;
			while(--i>-1){
				if(i!=index){
					_layers[i].style.position = "absolute";
					_layers[i].style.zIndex = i+1;
					_this.setDivVisibility(_layers[i], false);
				}else{
					_layers[i].style.position = "relative";
					_this.setDivVisibility(_layers[i], true);
				}
			}
		},

		/**************
		* btnObjManage
		* 1.btn object
		*/

		btnObjManage:	function(btn){
			var i = _btnObj.length;
			var bool = false;
			while(--i>-1){
				if(_btnObj[i]==btn){
					true;
					break;
				}
			}
			if(!bool) _btnObj.push(btn);
			i = _btnObj.length;
			while(--i>-1){
				if(_btnObj[i]==btn){
					_btnObj[i].className += " active";
				}else{
					_btnObj[i].className = _btnObj[i].className.substr(0,7);
				}
			}
		},

		/**************
		* setDivVisibility
		* 1.div object
		* 2.boolean
		*/

		setDivVisibility:	function(div, visible){
			(div.style||div).visibility=(visible)?
			 ((window.opera && !document.documentElement)?'visible':'inherit'):'hidden';
		}

	}
};
}

/*****************************************************************
	Common Functions
*****************************************************************/

	/**************
	* $(Get div object)
	* 1.String
	*/
	function $(nm){
		// IE5+, Mozilla, Opera
		if(document.getElementById) return document.getElementById(nm); 
		if(document.all) return document.all(nm); // IE4
		if(document.layers){ // NN4
			var s='';
			for(var i=1; i<arguments.length; i++)
				s+='document.layers.'+arguments[i]+'.';
			return eval(s+'document.layers.'+nm);
		}
		return null;
	}