var idPrev = "";
var elmPrev = null;

function fnOpen( id ){
  fnClose( idPrev );

  document.all.item(id).style.display = "block";

  idPrev = id;
  elmPrev = window.event.srcElement;
}
function fnClose( id ){
  if( id.length != 0 ){
    document.all.item(id).style.display = "none";
  }

  if( elmPrev != null ){
  }
}