function hidemenu(elmnt)
{
    if( document.getElementById(elmnt) != null)
    {
	document.getElementById(elmnt).style.visibility="hidden";
    }

}

function showmenu(elmnt)
{
    if( document.getElementById(elmnt) != null)
    {
/*	var el = document.getElementById(elmnt);
        var windowInnerHeight = document.body.clientHeight;
        var divHeight = document.getElementById(elmnt).offsetHeight;
        var windowTopPosition = document.body.scrollTop;
        var divOffsetPosition = 0; 
        while ((el=el.offsetParent) != null) { divOffsetPosition += el.offsetTop; }

        var result = 0;
        result = (divOffsetPosition - windowTopPosition) + divHeight;
        result = windowInnerHeight - result;
        if(result < 0)
            document.getElementById(elmnt).style.top = result;
        else
            document.getElementById(elmnt).style.top = 0;
*/   
        document.getElementById(elmnt).style.visibility="visible"; 
    }
}