Opening a form from another

In frmMain, add this method to receive the string:

internal void ReceiveString(string s)
{
   // put code in here to save and/or display the string somewhere, for example
   textBox1.Text = s;
}

In frmSecond, add this code to transmit the string (.NET 2.0 or later assumed):

frmMain main = (frmMain)Application.OpenForms["frmMain"];
main.ReceiveString(someString);

Great!

Thank you

Try:

frmSecond  f2 = new frmSecond();

f2.Show();

If you want frmSecond to maintain input focus until it is closed, use ShowDialog() instead of Show().