Pass value between forms

I have 2 forms (Main and Username).
My Main form has a mainMenu and a dropdown list (combobox) which displays usernames. The mainMenu allows an person to click the "Add User" menu item, which then displays my Username form, which is basically a simple input box, when the user clicks the Submit button on the Username form I want the username to be added to the cboUsers drop down box on the Main form...something like this.

Code:

---

In Username form

private void button1_Click(object sender, System.EventArgs e)
{
  //Add the username to the Main forms Username dropdown list
 
  Main.cboUsername.Items.Add(txtUsername.Text);       
}

---

but obviously, it doesn't work that way...any ideas on how to get this to work?

That code will work fine as long as:
1. Main is the name of an instance of the form class, not the name of the actual class.
2. cboUsername is declared as a public member instead of private or protected.

you need to declare the username form slightly differently when showing it, here's a quick example i knocked up for you...
in main ( IE the first Form )...

VB Code:

[Color=Blue]private[/COLOR] [Color=Blue]void[/COLOR] button1_Click([Color=Blue]object[/COLOR] sender, System.EventArgs e)
{
 
username frmUsers=[Color=Blue]new[/COLOR] username() ; [Color=blue]
base[/COLOR].AddOwnedForm(frmUsers); [Color=Green]//[/COLOR] [Color=Green]add[/COLOR] [Color=Green]it[/COLOR] [Color=Green]as[/COLOR] [Color=Green]an[/COLOR] [Color=Green]owned[/COLOR] [Color=Green]Form[/COLOR] [Color=Green].[/COLOR]
frmUsers.Show() ; 
 
}

in the username Form ...

VB Code:

[Color=Blue]private[/COLOR] [Color=Blue]void[/COLOR] button1_Click([Color=Blue]object[/COLOR] sender, System.EventArgs e)
{
 
main frmMain=(main)[Color=Blue]base[/COLOR].Owner; 
frmMain.cboUsername.Items.Add(txtUserName.Text) ; 
 
}

i'll include a zipped example to make it easier just incase :)

AHA! that was the problem...the modifier for the combobox was still set to private...Thanks!