if ( document.images )
{
  home_on = new Image ( );
  home_off = new Image ( );

  home_on.src = "images/home_on.gif";
  home_off.src = "images/home_off.gif";
  
  about_on = new Image ( );
  about_off = new Image ( );

  about_on.src = "images/about_on.gif";
  about_off.src = "images/about_off.gif";
  
  planning_on = new Image ( );
  planning_off = new Image ( );

  planning_on.src = "images/planning_on.gif";
  planning_off.src = "images/planning_off.gif";
  
  insurance_on = new Image ( );
  insurance_off = new Image ( );

  insurance_on.src = "images/insurance_on.gif";
  insurance_off.src = "images/insurance_off.gif";
  
  botbut1_on = new Image ( );
  botbut1_off = new Image ( );

  botbut1_on.src = "images/botbut1_on.gif";
  botbut1_off.src = "images/botbut1_off.gif";
  
  botbut2_on = new Image ( );
  botbut2_off = new Image ( );

  botbut2_on.src = "images/botbut2_on.gif";
  botbut2_off.src = "images/botbut2_off.gif";
  
  botbut3_on = new Image ( );
  botbut3_off = new Image ( );

  botbut3_on.src = "images/botbut3_on.gif";
  botbut3_off.src = "images/botbut3_off.gif";
  
  botbut4_on = new Image ( );
  botbut4_off = new Image ( );

  botbut4_on.src = "images/botbut4_on.gif";
  botbut4_off.src = "images/botbut4_off.gif";
  
  botbut5_on = new Image ( );
  botbut5_off = new Image ( );

  botbut5_on.src = "images/botbut5_on.gif";
  botbut5_off.src = "images/botbut5_off.gif";
}

function button_on ( imgId )
{
  if ( document.images )
  {
    butOn = eval ( imgId + "_on.src" );
    document.getElementById(imgId).src = butOn;
  }
}

function button_off ( imgId )
{
  if ( document.images )
  {
    butOff = eval ( imgId + "_off.src" );
    document.getElementById(imgId).src = butOff;
  }
}