TAB_HEADINGS = 'h2';
TAB_CLASS = 'tab';
SECTION_CLASS = 'section';
QUERY_SECTION_ARG = 'section';
TAB_SELECTED_CLASS = 'selected';
TAB_NOT_SELECTED_CLASS = 'not-selected';
LOADING_ELM_ID = 'loading';
CONTENT_HOLDER_ID = 'content-holder';
lastSection = 0

function checkHash() {
	var section = get_selected();
	if(section != lastSection) {
		show_section(section);
		lastSection = section;
	}
}

function get_elements() {
	var divs = document.getElementsByTagName("div");
	var htags = document.getElementsByTagName(TAB_HEADINGS);
	sections = [];
	tabs = [];
	headings = []
	for(var i=0; i<divs.length; i++) {
		if(divs[i].className == SECTION_CLASS) sections.push(divs[i]);
	}
	for(var i=0; i<htags.length; i++) {
		if(htags[i].className == TAB_CLASS) {
			var span = document.createElement("span");
			span.innerHTML = htags[i].innerHTML;
			tabs.push(span);
			headings.push(htags[i]);
		}
	}
}

function combine_tabs(){
	if(headings.length == 0)return;
	headings[0].innerHTML = '';
	for(var i=0; i<tabs.length; i++) {
		//headings[i].removeChild(tabs[i]);
		headings[0].appendChild(tabs[i]);
		if(i > 0) headings[i].parentNode.removeChild(headings[i]);
	}
}

function hide_all(){
	for(var i=0; i<sections.length; i++) {
		sections[i].style.display = "none";
	}
	for(var i=0; i<tabs.length; i++) {
		tabs[i].className = TAB_NOT_SELECTED_CLASS
	}
}

function show_section(index){
	hide_all()
	if(sections.length == 0) return;
	var section = sections[index];
	if(!section) var section = sections[index=0];
	section.style.display = "block";
	tabs[index].className = TAB_SELECTED_CLASS;
	var id = headings[index].getAttribute('id') || sections[index].getAttribute('id');
	if(id && index != lastSection) {
		var y = typeof window.pageYOffset != 'undefined' ? window.pageYOffset : document.documentElement.scrollTop;
		if(!navigator.userAgent.match(/Safari/)) location.hash = '#' + id;
		window.scrollTo(0, y);
		if(typeof load_tab == 'function') load_tab(id);
	}
	lastSection = index;
}

function tab_click(e){
	var target = e && e.target || event.srcElement;
	for(var i=0; i<tabs.length; i++) {
		if(target == tabs[i] || target.parentNode == tabs[i]){
			show_section(i);
		}
	}
}

function set_handlers(){
	for(var i=0; i<tabs.length; i++) {
		tabs[i].onclick = tab_click;
	}
}

function get_selected(){
	var selected = 0;
	if(location.hash) {
		selected = location.hash.substring(1);
	} else if(location.search) {
		var args = location.search.substring(1).split('&');
		for(var i=0; i<args.length; i++) {
			var name = args[i].split('=')[0];
			var value = args[i].split('=')[1];
			if(name == QUERY_SECTION_ARG){
				selected = value;
				break;
			}
		}
	}
	if(isNaN(selected)){
		for(var i=0; i<sections.length; i++){
			if(sections[i].getAttribute('id') == selected || headings[i].getAttribute('id') == selected){
				selected = i;
				break;
			}
		}
	}
	return selected;
}

function set_up() {
	get_elements();
	combine_tabs();
	var loadingElm = document.getElementById(LOADING_ELM_ID);
	if(loadingElm){
		loadingElm.style.display = "none";
	}
	var contentHolderElm = document.getElementById(CONTENT_HOLDER_ID);
	if(contentHolderElm) {
		contentHolderElm.style.display = "block";
	}
	var selected = get_selected();
	show_section(selected);
	set_handlers();
	if(!navigator.userAgent.match(/Safari/)) setInterval(checkHash, 100);
}

function insertSmile(oObject, oSimbol) {
	oObject.focus();
	if (window.document.all) {
		oSelection= window.document.selection.createRange();
		oSelection.text = oSimbol;
	} else if (navigator.appName == "Netscape") {
		sOldValue = new String(oObject.value);
		iStart= oObject.selectionStart;
		iEnd= oObject.selectionEnd;
		sNewValue = sOldValue.substring(0, iStart) + oSimbol + sOldValue.substring(iEnd, sOldValue.length);
		oObject.value = sNewValue;
	} else {
		oObject.value += oSimbol;
	}
}