function SwitchMenu(obj)
{
    if(document.getElementById)
    {
    var el = document.getElementById(obj);
    var ar = document.getElementById("masterdiv").getElementsByTagName("span");
  if(el.style.display != "block")
  {
     for (var i=3; i<ar.length; i++)
     {
    if (ar[i].className=="submenu")
    ar[i].style.display = "none";
     }
     el.style.display = "block";
  }
  else
  {
  el.style.display = "none";
  }
  }
}

function pokazOpis (ktorylink) {
if (document.getElementById) {
  if (ktorylink.opis) {
   document.getElementById('opisy').childNodes[0].nodeValue = ktorylink.opis;
  } else {
   document.getElementById('opisy').childNodes[0].nodeValue = ktorylink.childNodes[0].nodeValue;
  }
  return false;
} else {
  return true;
}
}

<div id="masterdiv">
<a onmouseover="return pokazOpis(this)" href="#" onclick="SwitchMenu('link1')"  opis="Jakis tam opis">LINK 1</a><br/>
<span class="submenu" id="link1">
&nbsp;&nbsp;&nbsp;&nbsp;<a href="podmenu1a.html" onmouseover="return pokazOpis(this)" opis="Inny piekny opis">link1a</a><br/>
<a href="podmenu1b.html">link1b</a><br/>
<a href="podmenu1c.html">link1c</a><br/>
<a href="podmenu1d.html">link1d</a><br/>
</span>

[HTML] pobierz, plaintext 
<p id="opisy">aaa</p>
[HTML] pobierz, plaintext 

document.getElementById('pole').innerHTML