// определение броузера пользователя
var browser = null; // 1 - MSIE; 2 - Opera; 3 - Gecko
function browser_define(){
	if (navigator.userAgent.match(/Opera/) != null) {
		return 2;
	}
	if (navigator.userAgent.match(/Gecko/) != null) {
		return 3;
	}
	if (navigator.userAgent.match(/MSIE/) != null) {
		return 1;
	}
	return 1; // default as IE
}
browser = browser_define();


/*****************************
**   Misc functions
******************************/
function $(id){
	return document.getElementById(id);	
}

function getPageY( oElement ) {
	var iPosY = oElement.offsetTop;
	while ( oElement.offsetParent != null ) {
		oElement = oElement.offsetParent;
		iPosY += oElement.offsetTop;
		if (oElement.tagName == 'BODY') break;
	}
	return iPosY;
}

function getPageX( oElement ) {
	var iPosX = oElement.offsetLeft;
	while ( oElement.offsetParent != null ) {
		oElement = oElement.offsetParent;
		iPosX += oElement.offsetLeft;
		if (oElement.tagName == 'BODY') break;
	}
	return iPosX;
}

function getMousePosition(e) {
	if (e.pageX || e.pageY){
		var posX = e.pageX;
		var posY = e.pageY;
	}else if (e.clientX || e.clientY) 	{
		var posX = e.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
		var posY = e.clientY + document.body.scrollTop + document.documentElement.scrollTop;
	}
	return {x:posX, y:posY}	
}

	
/*****************************
**   Event listeners
******************************/

/**
 * @param {Event} oEvt
 * @return {Event}
 */
function checkEvent(oEvt){
	oEvt=(oEvt) ? oEvt : ( (window.event) ? window.event : null );
	if(oEvt && oEvt.srcElement && !window.opera)
		oEvt.target=oEvt.srcElement;
	
	//Handle mouse wheel event
	if(oEvt){
		if(oEvt.wheelDelta){
			oEvt.mouse_wheel_delta=oEvt.wheelDelta/120;
			if(window.opera)
	        	oEvt.mouse_wheel_delta*=-1;
		}
		else if(oEvt.detail){
	    	oEvt.mouse_wheel_delta = -oEvt.detail/3;
		}
	}
	
	return oEvt;
}

/**
 * @param {Event} evt
 */
function cancelEvent(evt){
	if((evt=checkEvent(evt))){
		evt.cancelBubble=true;
		if(evt.cancelable){
			evt.preventDefault();
			evt.stopPropagation();
		}
	}
	return false;
}

function addEvent(objElement, strEventType, ptrEventFunc) {
	if (objElement.addEventListener)
		objElement.addEventListener(strEventType, ptrEventFunc, false);
	else if (objElement.attachEvent)
		objElement.attachEvent('on' + strEventType, ptrEventFunc);
}

function removeEvent(objElement, strEventType, ptrEventFunc) {
	if (objElement.removeEventListener) objElement.removeEventListener(strEventType, ptrEventFunc, false);
		else if (objElement.detachEvent) objElement.detachEvent('on' + strEventType, ptrEventFunc);
}

/*****************************
**   Common class methods
******************************/

function switchClass( objNode, strCurrClass, strNewClass ) {
	if ( matchClass( objNode, strNewClass ) ) replaceClass( objNode, strCurrClass, strNewClass );
		else replaceClass( objNode, strNewClass, strCurrClass );
}

function removeClass( objNode, strCurrClass ) {
	replaceClass( objNode, '', strCurrClass );
}

function addClass( objNode, strNewClass ) {
	replaceClass( objNode, strNewClass, '' );
}

function replaceClass( objNode, strNewClass, strCurrClass ) {
	var strOldClass = strNewClass;
	if ( strCurrClass && strCurrClass.length ){
		strCurrClass = strCurrClass.replace( /\s+(\S)/g, '|$1' );
		if ( strOldClass.length ) strOldClass += '|';
		strOldClass += strCurrClass;
	}
	objNode.className = objNode.className.replace( new RegExp('(^|\\s+)(' + strOldClass + ')($|\\s+)', 'g'), '$1' );
	objNode.className += ( (objNode.className.length)? ' ' : '' ) + strNewClass;
}

function matchClass( objNode, strCurrClass ) {
	return ( objNode && objNode.className.length && objNode.className.match( new RegExp('(^|\\s+)(' + strCurrClass + ')($|\\s+)') ) );
}

function getAncestorByClassName( oCurrentElement, sClassName, sTagName ) {
	var oCurrent = oCurrentElement.parentNode;
	while ( oCurrent.parentNode ) {
		if ( matchClass( oCurrent, sClassName ) && ( !sTagName || oCurrent.tagName.toLowerCase() == sTagName.toLowerCase() ) ) return oCurrent;
		oCurrent = oCurrent.parentNode;
	}
}

function getElementsByClassName(objParentNode, strNodeName, strClassName){
	var nodes = objParentNode.getElementsByTagName(strNodeName);
	if(!strClassName){
		return nodes;	
	}
	var nodesWithClassName = [];
	for(var i=0; i<nodes.length; i++){
		if(matchClass( nodes[i], strClassName )){
			//nodesWithClassName.push(nodes[i]);
			nodesWithClassName[nodesWithClassName.length] = nodes[i];
		}	
	}
	return nodesWithClassName;
}

function getElementsByClassNameFirstLevel(objParentNode, strNodeName, strClassName){
	var nodes = objParentNode.getElementsByTagName(strNodeName);

	if(!strClassName){
		nodesFirstLevel = [];
		for(var i=0; i<nodes.length; i++){
			if(nodes[i].parentNode.parentNode == objParentNode){
				nodesFirstLevel.push(nodes[i]);
			}	
		}
		return nodesFirstLevel;	
	}
	var nodesWithClassNameFirstLevel = [];
	for(var i=0; i<nodes.length; i++){
		if(matchClass(nodes[i], strClassName) && nodes[i].parentNode.parentNode == objParentNode){
			nodesWithClassNameFirstLevel.push(nodes[i]);
		}	
	}
	return nodesWithClassNameFirstLevel;
}

function getParentByClassName(element, className){
	var currentElement = element;
	while(currentElement.parentNode && !matchClass(currentElement.parentNode, className)){
		currentElement = currentElement.parentNode;
		if (currentElement.tagName.toLowerCase() == 'body') {
			return null;
			break;
		}
	}
	return currentElement.parentNode;
}

function getParentByTagName(element, tagName){
	var currentElement = element;
	while(currentElement.parentNode && currentElement.parentNode.tagName.toLowerCase() != tagName){
		currentElement = currentElement.parentNode;
		if (currentElement.tagName.toLowerCase() == 'body') {
			return null;
			break;
		}
	}
	return currentElement.parentNode;
}



/* Class inheritance */
Function.prototype.inheritFrom = function(BaseClass) { // thanks to Kevin Lindsey for this idea
  var Inheritance = function() {};
  Inheritance.prototype = BaseClass.prototype;

  this.prototype = new Inheritance();
  this.prototype.constructor = this;
  this.baseConstructor = BaseClass;
  this.superClass = BaseClass.prototype;
}


if(!Function.prototype.call) { // emulating 'call' function for browsers not supporting it (IE5)
	Function.prototype.call = function() {
		var oObject = arguments[0];
		var aArguments = [];
		var oResult;       
		oObject.fFunction = this;
		for (var i = 1; i < arguments.length; i++) {
			aArguments[aArguments.length] = 'arguments[' + i + ']';         
		}
		eval('oResult = oObject.fFunction(' + aArguments.join(',') + ')');
		oObject.fFunction = null;
		return oResult;
	}
};