TAB_LEFT   = 0;
TAB_MIDDLE = 1;
TAB_RIGHT  = 2;
var tabSelectedCallbacks = Array();
var tabClosedCallbacks = Array();
function getTabElements(tab){
	var myClass = "";
	switch(tab){
		case TAB_LEFT:
			myClass = "crn_main_top_tl";
			break;
		case TAB_MIDDLE:
			myClass = "crn_main_top_tm";
			break;
		case TAB_RIGHT:
			myClass = "crn_main_top_tr";
			break;
		default://TODO handle error wrong useage of the api
		return new Array(0);
	}
	return getElementsByClassName('div',myClass);
}
function tabsUnSelected(){
	var cb,i,k;
	var elements = getElementsByClassName('div','tabSelected');
	for (i = 0;i < elements.length;i++){
		removeClass(elements[i], 'tabSelected');
	}
	if(elements.length!==0){
		for ( k = 0; k < tabClosedCallbacks.length; k++){
			cb = tabClosedCallbacks[k]; 
			cb(getTabByElement(elements[0]));
		}
	}
}
function tabMouseOut(tab){
	var elements = getTabElements(tab);
	for (var i = 0;i < elements.length;i++){
		removeClass(elements[i],"tabHover");	
	}
}
var oldTab = -1;
function tabSelected(tab, runCallback){
	var elements = getTabElements(tab);
	tabsUnSelected();
	tabMouseOut(tab);
	for (var i = 0;i < elements.length;i++){
		addClass(elements[i],'tabSelected');
	}
	
	if( (oldTab!==tab || ( typeof runCallback != 'undefined' && runCallback === true ) ) && ( typeof runCallback == 'undefined' || runCallback !== false ) ){
		oldTab = tab;
		for(var k = 0; k < tabSelectedCallbacks.length; k++){
			var cb = tabSelectedCallbacks[k];
			cb(tab);
		}
	}
}
function getSelectedTabIndex(){ return oldTab; }
function tabMouseOver(tab){
	var elements = getTabElements(tab);
	var classes = elements[0].className.split(" ");
	for (var i = 0;i < classes.length;i++){
		if(classes[i] == "tabSelected"){return;}
	}
	for (var k = 0;k < elements.length;k++){
		addClass(elements[k],"tabHover");	
	}
}
//center right navi mouse over
function crnMover(element){
	var tab = getTabByElement(element);
	tabMouseOver(tab);
}
function crnMout(element){
	var tab = getTabByElement(element);
	tabMouseOut(tab);
}
function crnSel(element){
	var tab = getTabByElement(element);
	tabSelected(tab);
}
/**
@return String
returns the tab's class or null if a non tab ellement of the camnetwork navi is given as argument.
*/
function getTabByElement(element){
	var classes = element.className.split(" ");
	for (var i = 0;i < classes.length;i++){
		var myClass = classes[i];
		if(myClass=="crn_main_top_tl"){
			return 0;
		}
		else if(myClass=="crn_main_top_tm"){
			return 1;
		}
		else if (myClass=="crn_main_top_tr"){
			return 2;
		}
	}
}
function loadTabs(callback){
	request("GET", "http://www.camnetwork.org/en/tabs.js",null,function(tabs){
		var variables = eval("(" + tabs + ")");
		for (var attrib in variables){
			if(variables.hasOwnProperty(attrib)){
				var e = document.getElementById(attrib);
				if(e){e.innerHTML = variables[attrib];}
			}
		}
		if(callback!==null && typeof callback !=="undefined"){callback();}
	});
}
function setTabContent(content){
	if(typeof content !=="undefined"){
		$("crn_main_tabbed_main").innerHTML = content;
	}
}
function addTabSelectedCallback(callback){
	var i;
	var add = true;
	for( i = 0;add && i < tabSelectedCallbacks.length ; i++){
		add &= (tabSelectedCallbacks[i] !== callback);
	}
	if( add ){ 	tabSelectedCallbacks.push(callback); }
}
function addTabClosedCallback(callback){
	var i;
	var add = true;
	for(i = 0; add && i < tabClosedCallbacks.length ; i++){
		add &= (tabClosedCallbacks[i] !== callback);
	}
	if( add ){ tabClosedCallbacks.push(callback); }
}