JS函数的AJAX调用

I'm trying to call a javascript function from an html.erb file. The javascript function makes an Ajax call to a specified controller, sending an item id from the URL as a parameter.

I keep getting syntax and "can't find variable: callAjax" errors.

in the html.erb file

<%= image_tag('star.png', :style => 'margin-right: 10px', :onclick => "callAjax('/book/favorite/'+book.id);") %>  

in the js file

function callAjax(path) {
  console.log(path);
    $.ajax({
        url: 'localhost:3000'+path,
        data: path.substring(path.lastIndexOf('/') + 1),
        success:{
          //do something
        }
    });
}

in the book controller

  def favorite
    book=Book.find(params[:id])
    current_user.favorite_books << book
  end