var current_letter = null;
var timeout = null;

/*****************************************************************************/
function show_data( letter )
{
  if( timeout )
    window.clearTimeout( timeout );
  timeout = window.setTimeout(function(){
    if( current_letter )
      hide_data( current_letter );
    current_letter = letter;

    var div = document.getElementById("data_" + letter);
    div.style.display = "block";

    var link = document.getElementById("letter_" + letter);
    if( link )
    {
      link.style.fontWeight = "bold";
      link.childNodes[0].style.color = "#000000";
    }// end if()
  }, 200);
}// end show_data( letter )


/*****************************************************************************/
function hide_data( letter )
{
  var div = document.getElementById("data_" + letter);
  div.style.display = "none";

  var link = document.getElementById("letter_" + letter);
  if( link )
  {
    link.style.fontWeight = "";
    link.childNodes[0].style.color = "";
  }// end if()
}// end hide_data( letter )