I'm trying to interact with my smartcontract but get the error: Uncaught TypeError: MyContract.at is not a function

My Code:

```
var web3 = require('ethereum.js');
web3.setProvider(new web3.providers.HttpProvider());

var MyContract = web3.eth.contract([{"constant":false,"inputs":[{"name":"x","type":"uint256"}],"name":"set","outputs":[],"type":"function"},{"constant":true,"inputs":[],"name":"get","outputs":[{"name":"retVal","type":"uint256"}],"type":"function"}]);

var result = MyContract.at("MyContractAddress").get();
console.log(result);

```

When I request default Geth functionality I get a correct response:

```
var version = web3.version.api;
console.log(version);  "0.2.4"

```