Post with JSon swift

Question

I have a simple method to read JSon online.

func recorreJSon(){
    let requestURL: NSURL = NSURL(string: rutaJSon)!
    let urlRequest: NSMutableURLRequest = NSMutableURLRequest(URL: requestURL)
    let session = NSURLSession.sharedSession()
    let task = session.dataTaskWithRequest(urlRequest) {
        (data, response, error) -> Void in

        let httpResponse = response as! NSHTTPURLResponse
        let statusCode = httpResponse.statusCode

        if (statusCode == 200) {           
            do{

                let json = try NSJSONSerialization.JSONObjectWithData(data!, options:.AllowFragments)

                //print(json)

                if let misContactos = json["contactos"] as? [[String: AnyObject]] {
                ... Read jSon ...

But now I have webservice with login and values to search. For example. First I have to connect with user and pass ($User = $_POST["username"]...) and some parameters to limit my JSon.

But the problem is, how can I send my user and pass? Was reading about request.HTTPMethod = "POST" and

var bodyData = "username=myUsername&key2=value&key3=value"
request.HTTPBody = bodyData.dataUsingEncoding(NSUTF8StringEncoding);

Is this? I cant testing cause need VPN.

Thanks

EDIT:

Have this:

    let myUrl = NSURL(string: "http://www.swiftdeveloperblog.com/http-post-example-script/");let request = NSMutableURLRequest(URL:myUrl!);
    request.HTTPMethod = "POST";
    // Compose a query string
    let postString = "username=miUser&password=miPass";

    request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding);

    let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
        data, response, error in

        if error != nil
        {
            print("error=\(error)")
            return
        }else{



        // You can print out response object
        print("response = \(response)")

        // Print out response body
        let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
        print("responseString = \(responseString)")

        //Let’s convert response sent from a server side script to a NSDictionary object:

        var err: NSError?
        let myJSON = NSJSONSerialization.JSONObjectWithData(data!, options: .MutableLeaves) as? NSDictionary 

        if let parseJSON = myJSON {
            // Now we can access value of First Name by its key
            var firstNameValue = parseJSON["firstName"] as? String
            print("firstNameValue: \(firstNameValue)")
        }

            }

    }

    task.resume()

But in let myJSON = NSJSONSerialization.JSONObjectWithData(data!, options: .MutableLeaves) as? NSDictionary i have error "Call can throws, but is not marked with 'try' and the error is not handle"

If I put try, where have to put cath? always have error.