booksarr=new Array('1584280816','0393325512','0240516869','1558605339','0961392142','0471289280','1584280506','1592001068','0764516620','0764574140','1931868174','9059050649','0782141773','0762104937','1579906249','1579905803','0762106867','1843401487','0735619921','0471767743','0764543598','0782143482','0782144187','0764598023','1584281766','');

if(booksarr.length > 6){
function getRndImg() {
  var rnd = Math.round(Math.random()*(booksarr.length-1));
  return booksarr[rnd]
}
function makeArray() {
  var list = "";
  var arr = new Array();
  cnt = 0;
  while (cnt!=nofRandom) {
    var img = getRndImg();
    if (list.indexOf(img)==-1) {
      arr[cnt++]=img
      list+=img;
    }
  }
  return arr;
}
nofRandom = 6;


arr = makeArray();
for (i=0;i<arr.length;i++)
    {document.write('<iframe src="http://rcm.amazon.com/e/cm?t=masternewmedi&o=1&p=8&l=as1&asins=' + arr[i]+ '&fc1=000000&IS2=1&lt1=_blank&lc1=0000FF&bc1=000000&bg1=FFFFFF&f=ifr" style="width:120px;height:240px;" scrolling="no" marginwidth="0" marginheight="0" frameborder="0"></iframe><br><br>')}

}