Return a value from a child Form

Hopefully a simple one, but is perplexing me ... I have a main class that calls a logon form to validate users against a DB backend... The login form works fine but from my main class I want to return a value ( true or false ) from the login form to either allow the main MDI form to run or terminate the application. Not sure if my approach is correct, in fact being new to C# struggling quite alot with scope in general .. but any pointers gratefully received TIA Dave Main Cls frmLogon myfrmLogon =new frmLogon(); bool myretval = myfrmLogon.Show(); //Cannot implicitly convert type 'void' to 'bool' error here Logon Form private bool logon; private void frmLogon_Load(object sender, System.EventArgs e) { logon = false; } ///// Various logon form code removed that sets the logon varivle true or false private bool frmLogon_Closing(object sender,System.ComponentModel.CancelEventArgs e) { return logon; }