Webbrowser documenttext after invoking a submit button in the runtime

One Webbrowser1 control and one Textbox1 control is placed on a form.
In a sub, webbrowser1 navigates an url and shows its source in the textbox1.
In another sub, webbrowser1 navigates the same url, invoke a submit button in the webbrowser1, which append some controls and texts to the webbrowser1. Invoking does not change the url. After invoking the submit button, webbrowser1 is showing the added text correctly, but textbox1 does not updating the new source (after appending the new controls and texts). It shows the same old source.

private sub sub1name()

Webbrowser1.navigate(url)

//
do some work here
//

Textbox1.text = Webbrowser1.Documenttext

end sub




private sub sub2name()

Webbrowser1.navigate(url)

//
do some work here
//

WebBrowser1.Document.GetElementById("IDNAME").InvokeMember("click")
//this appends new control and text to the webbrowser1 by using javascript. Webbrowser1 displays the new added text correctly.

Textbox1.text = Webbrowser1.Documenttext
// Textbox1.text does not show the added controls and texts.
end sub