title: Calling function from already deployed contract in solidity?
body: <p>I want to know how to call a function from already deployed contract in solidity. I tried below one but it's throwing error and require without imorting the deployed contract</p>
  
  <pre><code> contract B {
      watch_addr = 0x1245689;
      function register(string _text) {
          watch_addr.call(bytes4(keccak256("register(string)")), _text);
      }
  }
  </code></pre>
  
  <p>Can any one please tell me the solution?</p>
  
  <pre><code>error:browser/delegate.sol:14:31: TypeError: Invalid type for argument in function call. Invalid implicit conversion from bytes4 to bytes memory requested. This function requires a single bytes argument. If all your arguments are value types, you can use abi.encode(...) to properly generate it.
         watch_addr.call(bytes4(keccak256(abi.encode("register(string)"))));
  </code></pre>