var NS4=(document.layers)?true:false;
var ttIE5=(document.all)?true:false;
var ttIE4=(navigator.userAgent.indexOf('MSIE 4') > 0)?true:false;


function showToolTip( toolTipContent, toolTipClass, evnt )
{
  tipLayer = getLayer( "tip" );
  toolTipClass = (typeof(toolTipClass) != "undefined") ? (" class=\"" + toolTipClass + "\"") : ("");
  toolTipMessage = "<div" + toolTipClass + ">" + toolTipContent + "</div>";
  writelayer( "tip", toolTipMessage );


  px = (evnt.x) ? evnt.x : evnt.pageX;
  px = (ttIE5 && !ttIE4) ? (px+document.body.scrollLeft) : (px);
  x = (px + 0);
  if( x < 0 )
  {
    x = 0;
  }

  py = (evnt.y) ? evnt.y : evnt.pageY;
  py = (ttIE5 && !ttIE4) ? (py+document.body.scrollTop) : (py);

  y = py+10;
  if( y < 0 )
  {
    y = 0;
  }

  // if layer won't fit on right or bottom of page,
  // move layer to left or top of mouse respectively
  if( x + getlayerwidth( "tip" ) >= getwindowwidth() )
  {
    x = px - getlayerwidth( "tip" );
  }
  if( y + getlayerheight( "tip" ) >= getwindowheight() )
  {
    y = py - getlayerheight( "tip" );
  }

  movelayer( "tip", x, y );

  showlayer( "tip" );
  return true;
}

function hideToolTip()
{
  hidelayer( "tip" );
  movelayer( "tip", 0, 0 );

}

function getLayer( id )
{
  var messageLayer = getElt( id );

  if( messageLayer == null )
  {
    messageLayer = document.createElement( "div" );

    messageLayer.setAttribute( "id", id );
    messageLayer.style.zIndex = 6;

    document.body.appendChild( messageLayer );
  }

  return messageLayer;
}