if (document.images)
{
  preload_image_object = new Image();
  // set image url
  image_url = new Array();
  image_url[0] = "_images/btn_home.jpg";
  image_url[1] = "_images/btn_homeOVR.jpg";
  image_url[2] = "_images/btn_rules.jpg";
  image_url[3] = "_images/btn_rulesOVR.jpg";
  image_url[4] = "_images/btn_categories.jpg";
  image_url[5] = "_images/btn_categoriesOVR.jpg";
  image_url[6] = "_images/btn_judging.jpg";
  image_url[7] = "_images/btn_judgingOVR.jpg";
  image_url[8] = "_images/btn_gala.jpg";
  image_url[9] = "_images/btn_galaOVR.jpg";  
  image_url[10] = "_images/btn_contact.jpg";
  image_url[11] = "_images/btn_contactOVR.jpg";
  image_url[12] = "_images/btn_enter.jpg";
  image_url[13] = "_images/btn_enterOVR.jpg";
  image_url[14] = "_images/btn_homeIN.jpg";
  image_url[15] = "_images/btn_homeINOVR.jpg";  

  var i = 0;
    for(i=0; i<=3; i++) 
      preload_image_object.src = image_url[i];
}


if (document.images) {
    hpup       = new Image();
    hpup.src   = "_images/btn_home.jpg" ;
    hpdown     = new Image() ;
    hpdown.src = "_images/btn_homeOVR.jpg" ;
    rulesup       = new Image();
    rulesup.src   = "_images/btn_rules.jpg" ;
    rulesdown     = new Image() ;
    rulesdown.src = "_images/btn_rulesOVR.jpg" ;
    catsup       = new Image();
    catsup.src   = "_images/btn_categories.jpg" ;
    catsdown     = new Image() ;
    catsdown.src = "_images/btn_categoriesOVR.jpg" ;
    judgeup       = new Image();
    judgeup.src   = "_images/btn_judging.jpg" ;
    judgedown     = new Image() ;
    judgedown.src = "_images/btn_judgingOVR.jpg" ;
    galaup       = new Image();
    galaup.src   = "_images/btn_gala.jpg" ;
    galadown     = new Image() ;
    galadown.src = "_images/btn_galaOVR.jpg" ;	
    contactup       = new Image();
    contactup.src   = "_images/btn_contact.jpg" ;
    contactdown     = new Image() ;
    contactdown.src = "_images/btn_contactOVR.jpg" ;
    enterup       = new Image();
    enterup.src   = "_images/btn_enter.jpg" ;
    enterdown     = new Image() ;
    enterdown.src = "_images/btn_enterOVR.jpg" ;
    hpinup       = new Image();
    hpinup.src   = "_images/btn_homeIN.jpg" ;
    hpindown     = new Image() ;
    hpindown.src = "_images/btn_homeINOVR.jpg" ;	

}
function buttondown( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "down.src" );
    }
}
function buttonup ( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "up.src" );
    }
}