var place=10;
var trig=4;
var need=0;

function setMenu(a)
{
	need=a;

	if(a<place) trig=-4;
	else trig=4;

	setTimeout('placeMenu("'+parseInt(a)+'")',5);
}
function placeMenu(a)
{
	$('menu_bot').setStyle({left: ''+parseInt(place)+'px'});
	if(place>=need+4 || place<=need-4)
	{
		place=place+trig;
		setTimeout('placeMenu("'+a+'")',5);

	}

}