Set focus on edit box after displaying message in Inno Setup

Question

I want to set the focus on the edit box again after displaying message.

portno := Edit.Text;
if (portno = '') then
begin
  MsgBox('Enter Port Number to proceed.', mbInformation, MB_OK);
  Result := False;
end

Answer 1

Set TForm.ActiveControl of the WizardForm:

WizardForm.ActiveControl := Edit;

This answer shows this in action:
Port range validation for data input in Inno Setup