.keyup(function()) don't work for me...nedd some help

.keyup(function()) don't work for me...nedd some help

Okay, so I'm learning jQuery and using it under Ruby on Rails. In my index.html.erb file I have this: 

  

   

    <form>
   

  

  

   

     <input id="target" type="text" value="Hello there">
   

  

  

   

    </form>
   

  

  

   

    <div id="other">
   

  

  

   

     Trigger the handler
   

  

  

   

    </div>

And then in my script.js, I have this: 

  

   

    $( "#target" ).keyup(function() {
   

  

  

   

     alert( "Handler for .keyup() called." );
   

  

  

   

    });

However, when I type something in the input box, nothing happens...no errors either.