You said your button element has a className
,you can get this element with like this:
public Form1()
{
InitializeComponent();
webBrowser1.Navigate("To your register account url");
}
int on = 0;
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
foreach (HtmlElement btn in webBrowser1.Document.GetElementsByTagName("button"))
{
if (btn.GetAttribute("className") == "yourclassname")
{
btn.InvokeMember("Click");
break;
}
}
}