I thought change to an input text box in view can reflect back to the can.Observe?

But somehow the following won't work:

2. <script type='text/ejs' id='template'>
3.     
4.   <input type="text" value="<%= foo.attr('bar') %>">
5. 
   
6. </script>
7. 
   
8. <script>
10. var foo = new can.Observe({ bar: "hello" });
11. 
    
12. var template = can.view("#template", {
13.     foo: foo
14. });
15. $(document.body).prepend(template);
16. 
    
17. </script>
18. 
    

the jsfiddle link will give a demo of the value of the can.Observe vs the input's value... somehow if a user types something in, it is not reflected in the can.Observe?   And is using EJS the only way to make two-way work?  Can Mustache be used to do it -- if somebody can make it work and give an example in the jsfiddle?