I've been tasked with porting a legacy Delphi application over to C# .Net. The original delphi developer left several months before I was hired. I'm receiving the E2010 Incompatible types: 'Integer' and 'Char' error for the below method. I'm trying to compile the application within the Delphi 2007 IDE, I've been told that original application is either Delphi 4 or 5 if that helps any. I understand what the error is telling me but I don't understand why\how it is applied to the code snippet below. Any help\direction would be greatly appreciated.

Thanks in advance

function StrIComp_JOH_PAS_1(const Str1, Str2: PChar): Integer;
var
  Ch1, Ch2 : Char;
  Offset   : Integer;
  PStr     : PChar;
begin;
  PStr   := Str1;
  Offset := Str2 - PStr;
  repeat
    Ch1 := Upper[PStr^];
    Ch2 := Upper[PStr[Offset]];
    if (Ch1 = #0) or (Ch1 <> Ch2) then
      Break;
     Inc(PStr);
  until False;
  Result := Integer(Ch1) - Integer(Ch2);
end;