if(document.images) {
 var imgs = new Array();
 imgs[0] = new Image();  imgs[0].src = "img/2006/m_home_a.gif";
 imgs[1] = new Image();  imgs[1].src = "img/2006/m_web_a.gif";
 imgs[2] = new Image();  imgs[2].src = "img/2006/m_contact_a.gif";
}

function chgimg(id, imgname) {
 if(document.images) {
  if(imgs[imgname]) {
    document.images[id].src = imgs[imgname].src;
    document.m_bottom.src = "img/2006/m_bottom_"+id+".gif";
  }
  else {
    document.images[id].src = imgname;
  }
 }
}