Como fazer a validação do cpf?

function CPF_Valido(strCPF: string): boolean;
var
  sDigInfo, sDigCalc: String[2];
  VetCPF: Array[1..11] of ShortInt;
  fCPF: Extended;
  wCPF_Total: Word;
  x: ShortInt;
  CodErro: Integer;
begin
  Val( strCPF, fCPF, CodErro );
  Str( fCPF :11 :0, strCPF );

  for x := 1 to 11 do
  begin
    if  Length( Trim(strCPF[x]) ) = 0 then
        VetCPF[x] := 0
    else
        VetCPF[x] := StrToInt( strCPF[x] )
    ;
  end;

  sDigInfo := IntToStr( VetCPF[10] ) + IntToStr( VetCPF[11] );

  wCPF_Total :=
    ( VetCPF[1] * 10 ) + ( VetCPF[4] * 7 ) + ( VetCPF[7] * 4 ) +
    ( VetCPF[2] *  9 ) + ( VetCPF[5] * 6 ) + ( VetCPF[8] * 3 ) +
    ( VetCPF[3] *  8 ) + ( VetCPF[6] * 5 ) + ( VetCPF[9] * 2 );

  wCPF_Total := wCPF_Total - ( wCPF_Total div 11 * 11 );

  if  wCPF_Total < 2 then
      VetCPF[10] := 0
  else
      VetCPF[10] := 11 - wCPF_Total
  ;

  wCPF_Total :=
    ( VetCPF[1] * 11 ) + ( VetCPF[4] * 8 ) + ( VetCPF[7]  * 5 ) +
    ( VetCPF[2] * 10 ) + ( VetCPF[5] * 7 ) + ( VetCPF[8]  * 4 ) +
    ( VetCPF[3] *  9 ) + ( VetCPF[6] * 6 ) + ( VetCPF[9]  * 3 ) +
    ( VetCPF[10] * 2 );

  wCPF_Total := wCPF_Total - ( wCPF_Total div 11 * 11 );

  if  wCPF_Total < 2 then
      VetCPF[11] := 0
  else
      VetCPF[11] := 11 - wCPF_Total
  ;

  sDigCalc := IntToStr( VetCPF[10] ) + IntToStr( VetCPF[11] );

  Result := sDigCalc = sDigInfo
end;


Espero ter ajudado...!!!

Valeu aí ajudou bastante. OBrigado!!!