Confirm box on click anchor link to delete record

HTML  Code

<a href="javascript:void(0);" onclick="delete(<?php echo $row->id;?>);">Delete</a>

Javascript Code

<script type="text/javascript">
    var url="<?php echo base_url();?>";
    function delete(id){
       var r=confirm("Do you want to delete this?")
        if (r==true)
          window.location = url+"user/deleteuser/"+id;
        else
          return false;
        } 
</script>