function showMenu(divid){
    if((navigator.userAgent.match(/iPhone/i)) || (navigator.userAgent.match(/iPod/i))) {
        var divity=document.getElementById(divid)
        if(divity.style.display!='block'{
            divity.style.display='block'
        }
    }
}

function hideMenu(divid){
    if((navigator.userAgent.match(/iPhone/i)) || (navigator.userAgent.match(/iPod/i))) {
        document.getElementById(divid).style.display='none'
    }
}