title: CopyFile flagged as undeclared identifier
body: <p>Created a Copy Function and when trying to use 'CopyFile' in it, at point of compiling, Delphi flags it as undeclared identifier.</p>
  
  <p>Am I doing something wrong?</p>
  
  <pre><code>function TdmData.CopyAFile(Sourcefile, DestFile: string): boolean;
  var Src, Dest : PChar;
  begin
    Src := StrAlloc(Length(SourceFile)+1);
    Dest := StrAlloc(Length(DestFile)+1);
  try
    StrPCopy(Src,SourceFile);
    StrPCopy(Dest,DestFile);
  
    result := (CopyFile(Src,Dest,FALSE));
  finally
    StrDispose(Src);
    StrDispose(Dest);
  end;
  end;
  </code></pre>
  
  <p>Any help would be much appreciated,
  Thanks.</p>