Delete Duplicate values in array using Javascript

<script>
var str1=[5,6,5,6,8,9,7,8,9];
  var arr = str1.split(',');	
  var i,
      len=arr.length,
      out=[],
      obj={};
 
  for (i=0;i<len;i++)
  {
    obj[arr[i]]=0;
  }
  for (i in obj) 
 {
    out.push(i);
  }
  alert(out);
</script>