var timer = new Array();
	var y = new Array();
	var patternY = new Array();
	var delay = 25;
	patternY[2] = Array(-8, -5, -2, -1, 0, -1, -2, -3, -4);
	patternY[0] = Array(-8, -8, -7, -7, -6, -6, -5, -5, -4);
	var stepsY = patternY[2].length - 1;

	function bounce_start(element)
	{
		if (getObj('li' + element).className == 'navin')
		{
			return;
		}
		else
		{
			y[element] = 0;
			clearTimeout(timer[element]);
			timer[element] = setTimeout('changePosY(' + element + ', 1)', delay);
		}
	}
	
	function bounce_finish(element)
	{
		if (getObj('li' + element).className == 'navin')
		{
			return;
		}
		else
		{
			y[element] = stepsY;
			clearTimeout(timer[element]);
			timer[element] = setTimeout('changePosY(' + element + ', -1)', delay);
		}
	}
	
	function changePosY(element, inc)
	{
		y[element] += inc;
		getObj('a' + element).style.backgroundPosition = '0px ' + patternY[inc + 1][y[element]] + 'px';
		if (y[element] == 0 || y[element] == stepsY)
		{
			clearTimeout(timer[element]);
		}
		else
		{
			timer[element] = setTimeout('changePosY(' + element + ', ' + inc + ')', delay);
		}
	}
	
	function getObj(id)
	{
		return document.getElementById(id);
	}