API-Problem 1512 CPU

Right now im doing the simplest example, but cant get it to work. I try to use the Api Browse method, which according to the manual You could use without tokens and being logged in.

All I get from the Server is error 400 - bad request. Im not new to programming, but this doesnt work. If I could get it to work, the benefits would be huge. Please help!

I dont use JavaScript but C#. That shoudnt really matter though. At least thats what I Think :)

So I guess this is the classical question, "Why doesnt my code work"? 

private void connectButton_Click(object sender, EventArgs e)
{

System.Net.HttpWebRequest webRequest;
string requestParams = ""; 

requestParams = "{method:\"Api.Browse\"}";
string answer = "";
webRequest = (System.Net.HttpWebRequest)WebRequest.Create("https://ipadress/api/jsonrpc");

System.Net.ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };

webRequest.Method = "POST";
webRequest.ContentType = "application/json";

byte[] byteArray = Encoding.UTF8.GetBytes(requestParams);
webRequest.ContentLength = byteArray.Length;
using (Stream requestStream = webRequest.GetRequestStream())
{
requestStream.Write(byteArray, 0, byteArray.Length);
}

// Get the response.
using (WebResponse response = webRequest.GetResponse())
{
using (Stream responseStream = response.GetResponseStream())
{
StreamReader rdr = new StreamReader(responseStream, Encoding.UTF8);
answer = rdr.ReadToEnd(); // response from server

}
}

console.AppendText(answer,Color.Aquamarine,true);
}