id=0;
function opwin( obj_id )
{
        var el = document.getElementById(obj_id);

  if (el.style.display == "none")
        {
          el.style.display="";
        }
        else
        {
                el.style.display="none";
        }
}


<!--
function BGSound (playsound)
{
 var ID = "";
 var Brwsr = window.navigator.appName;
 if (document.all)
  {
    ID = "soundIE";
  }
 else
  {
    ID="soundElse";
  }
 if(playsound)
  {
    document.getElementById(ID).src="http://www.ixi.ua/audio/ixi.mp3";
  }
 else
  {
    document.getElementById(ID).src='';
  }
}
//-->