_button_default=null;
_isMenuActive=false;
_active_button=null;
imageOK=true;

function Button_on(){
	if (!imageOK) return;
	if (_active_button!=null)
		_active_button.off();
	_isMenuActive=true;
	_active_button=this;
	document[this.name].src=this.onImage.src;
}

function _defButtonOn(){
	if (_button_default==null)
		return;
		
	_button_default.on();
}


function Button_off(){
	if (!imageOK) return;
	_isMenuActive=false;
	_active_button=null;
			
	document[this.name].src=this.offImage.src;
	timerID=setTimeout('if (!_isMenuActive) _defButtonOn()', 1);
}
	
function setDefaultButton(button){
	if (imageOK==false){
		return;
	}
	_button_default=button;
	_active_button=_button_default;
	_button_default.defImage.src=_button_default.onImage.src;
	_button_default.on();
}

function Button(onName, offName, name){
	this.on=Button_on;
	this.off=Button_off;
	if (!document.images){
		imageOK=false;
		return;
	}
	this.nameOn=onName;
	this.nameOff=offName;
	this.name=name;
	this.on=Button_on;
	this.off=Button_off;
	this.onImage=new Image();
	this.onImage.src=this.nameOn;
	this.offImage=new Image();
	this.offImage.src=this.nameOff;
	this.defImage=new Image();
	this.defImage.src=null;
	
}

Navigation_ByTown = new Button("Images/Navigation/ByTown_Hover.gif", "Images/Navigation/ByTown.gif", "Image_Navigation_ByTown");
Navigation_ByRegion = new Button("Images/Navigation/ByRegion_Hover.gif", "Images/Navigation/ByRegion.gif", "Image_Navigation_ByRegion");
Navigation_ByType = new Button("Images/Navigation/ByType_Hover.gif", "Images/Navigation/ByType.gif", "Image_Navigation_ByType");
Navigation_ByHost = new Button("Images/Navigation/ByHost_Hover.gif", "Images/Navigation/ByHost.gif", "Image_Navigation_ByHost");
Navigation_ByChamber = new Button("Images/Navigation/ByChamber_Hover.gif", "Images/Navigation/ByChamber.gif", "Image_Navigation_ByChamber");
Navigation_Search = new Button("Images/Navigation/Search_Hover.gif", "Images/Navigation/Search.gif", "Image_Navigation_Search");
Navigation_Home = new Button("Images/Navigation/Home_Hover.gif", "Images/Navigation/Home.gif", "Image_Navigation_Home");

Navigation_Update = new Button("Images/Navigation/Update_Hover.gif", "Images/Navigation/Update.gif", "Image_Navigation_Update");
Navigation_View = new Button("Images/Navigation/View_Hover.gif", "Images/Navigation/View.gif", "Image_Navigation_View");
Navigation_QuickAdd = new Button("Images/Navigation/QuickAdd_Hover.gif", "Images/Navigation/QuickAdd.gif", "Image_Navigation_QuickAdd");
Navigation_BulkAdd = new Button("Images/Navigation/BulkAdd_Hover.gif", "Images/Navigation/BulkAdd.gif", "Image_Navigation_BulkAdd");
Navigation_Chambers = new Button("Images/Navigation/Chambers_Hover.gif", "Images/Navigation/Chambers.gif", "Image_Navigation_Chambers");
Navigation_Types = new Button("Images/Navigation/Types_Hover.gif", "Images/Navigation/Types.gif", "Image_Navigation_Types");
Navigation_Towns = new Button("Images/Navigation/Towns_Hover.gif", "Images/Navigation/Towns.gif", "Image_Navigation_Towns");
Navigation_ChangeLogin = new Button("Images/Navigation/ChangeLogin_Hover.gif", "Images/Navigation/ChangeLogin.gif", "Image_Navigation_ChangeLogin");
Navigation_LogOff = new Button("Images/Navigation/LogOff_Hover.gif", "Images/Navigation/LogOff.gif", "Image_Navigation_LogOff");
Navigation_MyInfo = new Button("Images/Navigation/MyInfo_Hover.gif", "Images/Navigation/MyInfo.gif", "Image_Navigation_MyInfo");
Navigation_Link = new Button("Images/Navigation/Link_Hover.gif", "Images/Navigation/Link.gif", "Image_Navigation_Link");