function open_submenu(sm)
{
document.getElementById("yog").style.display="none";
document.getElementById("zan").style.display="none";
document.getElementById("mag").style.display="none";
document.getElementById("pub").style.display="none";
document.getElementById(sm).style.display="block";
}

function prer(closing)
{
setTimeout("close_submenu(\""+closing+"\")",3000);
}

function close_submenu(oi)
{
var el=document.getElementById(oi);
el.style.display="none";
}