Login to gmail account through win form c# application

Question

Hi everyone, I want to make a win form application in it I have webBrowser1 control. I want to login to gmail account through my win form c# app. When I goes through this code I hope my code is well but who to getElementById of username and password from gmail.com

 

private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)

{

 

HtmlDocument hd = webBrowser1.Document;

HtmlElement username = hd.GetElementById("userNameTextBoxId");// how to find id from                                                                                                                             //gmail.com

HtmlElement pass = hd.GetElementById("passwordTextBoxId");         // I goes through inspect 

HtmlElement submit = hd.GetElementById("BtnId");      // elements but m unable to find id's

username.SetAttribute("value", "[email protected]");

pass.SetAttribute("value", "mypassword");

submit.InvokeMember("click");

 

 }

Please help me. I am worried about it.