folder  = "bausteine/";
 arrPics = new Array("pic01","pic02","pic03","pic04","pic05","pic06","pic07","pic08","pic09","pic10","pic11","pic12","pic13","pic14","pic15","pic16","pic17","pic18","pic19","pic20","pic21","pic22","pic23","pic24","pic25","pic26","pic27","pic28","pic29");
 arrlength = arrPics.length;
 spalte = 3;
 zeile = 4;
 speed = 450;

function change() {
 temp2 = (Math.random() * (spalte-1))+1;
 xkoordinate = Math.round(temp2);
 temp3 = (Math.random() * (zeile-1))+1; 
 ykoordinate = Math.round(temp3);
 nameofimage = 'x'+xkoordinate+'y'+ykoordinate;
 var temp4 = (Math.random() * (arrlength-1)); 
 var zahl4 = Math.round(temp4);
 window.document[nameofimage].src = folder + arrPics[zahl4]+'.jpg';
 setTimeout('change()', speed);
}

document.write('<table border=0 cellspacing=0 cellpadding=0>');
for (i=1;i<spalte+1;i++) {
  document.write('<tr>');
  for (j=1;j<zeile+1;j++) {
    var temp = (Math.random() * (arrlength-1)); 
    var zahl = Math.round(temp); 
    document.write('<td><img src="'+ folder +arrPics[zahl]+'.jpg" alt="x' + i +'y'+ j + '" border=0 height="75" width="95" name="x' + i + 'y' + j + '"></td>');
  }
 document.write('</tr>');
}
document.write('</table>');