You would probably require some AJAX to perform asynchronous get requests to retrieve data from /users/delete and /users/new from index.php
You could use JQuery plugin (http://jquery.com/) to make AJAX calls simpler as well
This is an example of a javascript that uses JQuery $.get() which makes an asynchronous get requesst
<html>
<head>
...import jquery javascript plugin...
<script>
//executes init() function on page load
$(init);
function init(){
//binds click event handlers on buttons where id = new and delete
// click function exectutes createUser or deleteUser depending on the
button that has been clicked
$('#new').click(function(){createUser();});
$('#delete').click(function(){deleteUser();});
}
function createUser(){
//submits a get request to users/new and alerts the data returned
$.get('users/new',function(data){alert('user is created : '+data)});
}
function deleteUser(){
//submits a get request to users/delete and alerts the data returned
$.get('users/delete',function(data){alert('user is deleted : '+data)});
}
</script>
</head>
<body>
<input id='new' type='button' />
<input id='delete' type='button' />
</body>
</html>