re = /^[^.]+(\.[^.]+)*@([^.]+[.])+[a-z]{2,4}$/;

  function xButOver(to) {
    to.src = "pic2/"+to.name+"p.jpg";
  }

  function xButOut(to) {
    to.src = "pic2/"+to.name+".jpg";
  }

  function ButOver(to) {
    to.style.backgroundImage = "url('pic2/butt2_over.png')"; 
  }

  function ButOut(to) {
    to.style.backgroundImage = "url('pic2/butt2.png')"; 
  }