improve example

README.md

@@ -22,7 +22,7 @@ Using it in Node.js:
 ```javascript
 var bitcore = require('bitcore');
 
-assert(bitcore.Address.isValid(address));
+assert(bitcore.Address.isValid('126vMmY1fyznpZiFTTnty3cm1Rw8wuheev'));
 var simpleTx = new bitcore.Transaction();
 var simpleTx.from(unspent).to(address, amount);
 simpleTx.sign(privateKey);