function RandNum(max) {
  key = Math.floor(Math.random() * max);
  return key;
}
function RandomPicture() {

  images = new Array( 3 );

  images[0] = "<img src='bilder/splash_04.jpg' alt='Splash'>";
  images[1] = "<img src='bilder/splash_05.jpg' alt='Splash'>";
  images[2] = "<img src='bilder/splash_05.jpg' alt='Splash'>";


  key = RandNum( images.length );

  document.write( images[ key ] );
}