gistfile1.js

<polymer-element name="my-element-wikipedia">

    <template>

        <style>h2 { color: black; } </style>        

        <button on-click="{{buttonClick}}"><h2>Hello from my prototyped element!</h2></button>

    </template>

    <script src="wikipedia.js"></script>

    <script>

    Polymer('my-element-wikipedia', {

    	buttonClick: function() { 

    		alert('howdy folks!'); 

    	}

    });

    </script>

</polymer-element>