Anzahlunten = 218;

mouseoveru1 = '<img onmouseover="auf(';
mouseoveru2 = ')" onmouseout="zu(';
mouseoveru3 = ')"';
mouseoveru4 = ' src="images/random/welpen/bild';
mouseoveru5 = '.jpg" border="0" width="100" height="75" alt="Weisse Schäferhunde Welpen">';

function randombildun() {
var a = Math.ceil(Math.random() * Anzahlunten);
document.write(mouseoveru1 + "'rbu" + a + "'" + mouseoveru2 + "'rbu" + a + "'" + mouseoveru3 + mouseoveru4 + a + mouseoveru5 + " ");
}