How can I programatically open a web page after injecting some data into it?

[lucky6969b]

I tried the following

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace SubmitForm
{
    public partial class Form1 : Form
    {
       	public Form1()
	{
		InitializeComponent();
			
	} 

	private void XYZ(object sender, WebBrowserDocumentCompletedEventArgs e) // fail was here.
	{
	    WebBrowser b = (WebBrowser)sender;
            b.Document.GetElementById("fullname").InnerText = "jacky";
	    //b.document.GetElementById("btnSubmit").InvokeMember("click");

             

	}

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button1_Click_1(object sender, EventArgs e)
        {
            WebBrowser browser = new WebBrowser();
            string target = "http://localhost/wwwroot/2/hello.html";
            browser.Navigate(target);
            browser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(XYZ);					
            System.Diagnostics.Process.Start("http://localhost/wwwroot/2/hello.html");	 
        }

   }
    
}

When the button is clicked, the web page is displayed, but the element with id "fullname" is still blank,
but not "Jacky"
Thanks
Jack