function newImage(arg) {
  if (document.images) {
    rslt = new Image();
    rslt.src = arg;
    return rslt;
  }
}

function changeImages() {
  if (document.images && (preloadFlag == true)) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
    }
  }
}

var preloadFlag = false;
function preloadImages() {
  if (document.images) {
    home_over = newImage("images/menu-home2.jpg");
    pricing_over = newImage("images/menu-pricing2.jpg");
    portfolio_over = newImage("images/menu-portfolio2.jpg");
    skills_over = newImage("images/menu-skills2.jpg");
    team_over = newImage("images/menu-team2.jpg");
    contact_over = newImage("images/menu-contact2.jpg");
    preloadFlag = true;
  }
}