﻿if (document.getElementById && document.getElementsByTagName) {
if (window.addEventListener) window.addEventListener('load', initAnims, false);
else if (window.attachEvent) window.attachEvent('onload', initAnims);
}

function initAnims() {
	

	classChange(document.getElementById('bottom_menu'),'scriptactive','noscript')
	var animElements = document.getElementById('bottom_menu').getElementsByTagName('ul');
	for(var i=0; i<animElements.length; i++) {
		animElements[i].bgAnim = {
		iPos:[0,0], 
		pUnit:['%','px'], 
		cFrame:0, 
		mFrame: 31,
		dPos:[0,-60],
		mSec:250
		}
		animElements[i].onmouseover = backPosAnimF;
		animElements[i].onmouseout = backPosAnimR;
		}


	function backPosAnimF() {
		doBackPosAnim(this,this.bgAnim,this.bgAnim.cFrame, this.bgAnim.mFrame);
	}
	
	function backPosAnimR() {
		doBackPosAnim(this,this.bgAnim,this.bgAnim.cFrame, 0);
	}
	
	
}

function doBackPosAnim(elem,vrH,startFrm,endFrm) {
	if (vrH.intID) window.clearInterval(vrH.intID);
	var actStep = 0, steps = Math.abs(endFrm - startFrm)+1;
	vrH.intID = window.setInterval(
		function() {
			vrH.cFrame = easeInOut(startFrm,endFrm,steps,actStep,1);
			vrH.cPos = [
				vrH.iPos[0]+vrH.cFrame*vrH.dPos[0], 
				vrH.iPos[1]+vrH.cFrame*vrH.dPos[1] 
 				];
			elem.style.backgroundPosition = vrH.cPos[0]+vrH.pUnit[0]+' '+vrH.cPos[1]+vrH.pUnit[1];
			actStep++;
			if (actStep > steps) window.clearInterval(vrH.intID);
		}
		,vrH.mSec)
}

function doBackPosChange(elem,vrH,startPos,endPos,steps,intervals,powr) {
	if (vrH.intID) window.clearInterval(vrH.intID);
	var actStep = 0;
	vrH.intID = window.setInterval(
		function() {
			vrH.cPos = [
				easeInOut(startPos[0],endPos[0],steps,actStep,powr),
				easeInOut(startPos[1],endPos[1],steps,actStep,powr)
				];
			elem.style.backgroundPosition = vrH.cPos[0]+vrH.pUnit[0]+' '+vrH.cPos[1]+vrH.pUnit[1];
			actStep++;
			if (actStep > steps) window.clearInterval(vrH.intID);
		}
		,intervals)
}

function easeInOut(minValue,maxValue,totalSteps,actualStep,powr) {
	totalSteps = Math.max(totalSteps,1)
	var delta = maxValue - minValue;
	var stepp = minValue+(Math.pow(((1 / totalSteps)*actualStep),powr)*delta);
	return Math.ceil(stepp)
}

function classChange(elem,addClass,remClass) {
	if (!elem.className) elem.className = '';
	var clsnm = elem.className;
	if (addClass && !clsnm.match(RegExp("\\b"+addClass+"\\b"))) clsnm = clsnm.replace(/(\S$)/,'$1 ')+addClass;
	if (remClass) clsnm = clsnm.replace(RegExp("(\\s*\\b"+remClass+"\\b(\\s*))*","g"),'$2');
	elem.className=clsnm;
	}

function showError(str) {
if (window.opera) opera.postError('|'+str+'|');
else alert('|'+str+'|');
}