function
show_off(image_name)
{
  if (document.images)
  {

    document[image_name].src = eval(image_name+"off.src");
  }
}

function
show_on(image_name)
{
  if (document.images)
  {
    document[image_name].src = eval(image_name+"on.src");
  }
}


// Create global variables Set of images
//if (document.images) Pre-load images.
{
  var menu_mainoff = new Image();
  var menu_aboutoff = new Image();
  var menu_profileoff = new Image();
  var menu_projectoff = new Image();
  var menu_lvloff = new Image();
  var menu_itoff = new Image();
  var menu_leoff = new Image();
  var menu_labsoff = new Image();
  var menu_spreadoff = new Image();
  var menu_supplyoff = new Image();
        
  var menu_mainon = new Image();
  var menu_abouton = new Image();
  var menu_profileon = new Image();
  var menu_projecton = new Image();
  var menu_lvlon = new Image();
  var menu_iton = new Image();
  var menu_leon = new Image();
  var menu_labson = new Image();
  var menu_spreadon = new Image();
  var menu_supplyon = new Image();
  
  menu_mainoff.src = "buttons/main_page.gif";
  menu_aboutoff.src = "buttons/about_us.gif";
  menu_profileoff.src = "buttons/staff_profiles.gif";
  menu_projectoff.src = "buttons/projects.gif";
  menu_lvloff.src = "buttons/lincoln_ventures.gif";
  menu_itoff.src = "buttons/it.gif";
  menu_leoff.src = "buttons/environmental.gif";
  menu_labsoff.src = "buttons/project_labs.gif";
  menu_spreadoff.src = "buttons/spreadmark.gif";
  menu_supplyoff.src = "buttons/supply.gif";
  
  menu_mainon.src = "buttons/main_page_ON.gif";
  menu_abouton.src = "buttons/about_us_ON.gif";
  menu_profileon.src = "buttons/staff_profiles_ON.gif";
  menu_projecton.src = "buttons/projects_ON.gif";
  menu_lvlon.src = "buttons/lincoln_ventures_ON.gif";
  menu_iton.src = "buttons/it_ON.gif";
  menu_leon.src = "buttons/environmental_ON.gif";
  menu_labson.src = "buttons/project_labs_ON.gif";
  menu_spreadon.src = "buttons/spreadmark_ON.gif";
  menu_supplyon.src = "buttons/supply_ON.gif";
}