JQuery same click function for multiple similar id

Question

I have a function like that to apply same event for multiple id with same attribute name.

<button id="hello">hello</button>
<button id="hello">hello</button>

and this is the JQuery function

$("#hello").click(function(event){
          window.alert("hello");
      });

but affects the first id. Someone know how I can perform the same effect for both ids.

Thanks