improved contracts interface

example/index.html

@@ -30,7 +30,7 @@
 </script>
 </head>
 <body>
-    <h1>balance</h1>
+    <h1>coinbase balance</h1>
     <button type="button" onClick="watchBalance();">watch balance</button>
     <div></div>
     <div id="original"></div>