function StrScan(Str: PChar; Chr: Char): PChar; assembler;
asm
        PUSH    EDI
        PUSH    EAX
        MOV     EDI,EAX
        OR      ECX, -1
        XOR     AL,AL
        REPNE   SCASB
        NOT     ECX
        POP     EDI
        XCHG    EAX, EDX
        REPNE   SCASB
        XCHG    EAX, EDI
        POP     EDI
        JE      @@1
        XOR     EAX, EAX
        RET
@@1:    DEC     EAX
end {$IFDEF F_P} [ 'EAX', 'EDX', 'ECX' ] {$ENDIF};