Taking .Text information from one form to another form

Well you have not even shown the child form yet. So it's unlikely that the textbox has been filled in (or if it has even been created yet).

Also, instead of accessing the child control in that form directly, expose a public property that returns the text from the textbox. After you show the form, access the form's public property to get the text you want and then assign it to the userName field.

In the child dialog, expose the text as follows:

public string Username
{
    get
    {
        return textBoxUsername.Text;
    }
}

Now in the parent dialog do this:

string userName;

var dialog = new ChildForm();
if (dialog.ShowDialog() == DialogResult.OK)
{
    userName = dialog.Username;
}

This won't work. What you are doing is creating a new instance of the form and trying to read the values from it which would be empty (if the default answer is empty).

Have a look here. This should help you.

Probably what you need to do something like this:

string GetPassword() {
    frm_LogonScreen dialog = new frm_LogonScreen();
    if (dialog.ShowDialog() == DialogResult.OK)
        return dialog.txt_UserName.Text;
    else
        return null;
}

You should use modal, dialog-like behavior. Obtain the result and put it whenever you need, null would mean failure to authenticate

—SA