Disallow empty and spaces-only input on Inno Setup custom page

Question

Is there a way to disallow user input if it contains spaces only? I already tried this solution:
Inno Setup - Create User Input Query Page with input length and format limit and use the input

But, I don't want that solution because it disable -space- completely.
E.g. if input in text field is "my name" it will return error because -space- is not allowed.

Answer 1

Use the same code as in:
Inno Setup - Create User Input Query Page with input length and format limit and use the input

Just use this implementation of ValidateInput:

function ValidateInput(Sender: TWizardPage): Boolean;
begin
  Result := True;

  if Trim(Page.Values[0]) = '' then
  begin
    MsgBox('Input cannot be empty.', mbError, MB_OK);
    Result := False;
  end;
end;

The Trim function is the key.