Flex RESTKit - login completely via SOAP and use REST callout

loginsoap.as

public function login():void {
	var lr:LoginRequest = new LoginRequest();
	lr.username = 'YOUR USERNAME';
	lr.password = 'YOUR PASSWORD';
	lr.callback = new com.salesforce.AsyncResponder(doQuery,showError);
				
	force.login(lr); 
	}

private function doQuery(result:LoginResult):void {
	rest = new RESTConnection();
	rest.setSession(result.sessionId,result.serverUrl);
	rest.query("SELECT ID, Name from Contact LIMIT 5",new mx.rpc.AsyncResponder(queryHandler,com.force.utility.util.genericError));
			}