delphi 05 q

im a noob @ this, nd i want make it so mi background is a certain file in a 
certain folder so that way if i change the design it will b updated in the p
rog im making. i was told to use this:

procedure TForm1.FormActivate(Sender: TObject);
begin
Image1.Picture. LoadFromFile(ExtractFilePath(Application
.ExeName) + '' + 'Ba
ckground.bmp');
end
 and i got these errors

[Warning] Unit1.pas(212): W1002 Symbol 'IncludeTrailingBackslash' is specific to a pl
atform
[Error] Unit1.pas(217): E2003 Undeclared identifier: 'FormActivate'
[Error] Unit1.pas(217): E2029 ';' expected but '(' found
[Error] Unit1.pas(219): E2003 Undeclared identifier: 'Image1'
[Error] Unit1.pas(219): E2066 Missing operator or semicolon
[Fatal Error] Project1.dpr(5): F2063 Could not compile used unit 'Unit1.pas'

does any know either a solution or another way to answer to my q thx in adva
nce