<script language='JavaScript'>
var r_text = new Array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30);

var cnt=0;
var printed=new Array();

while(true)
{
  var s=Math.floor(30*Math.random());

  if(!printed[s])
  {
    document.write(r_text[s]+"<br>");
    printed[s]=1;
    cnt++;
  }

  if(cnt==19)
    break;
}
</script>