Maziar,
at a first glance parentheses {} within serial() function don't match. It seems that lines:
>>
else if (buf != *(SDPointer -1)) goto ERSP;
if (buf == 0x66){
//some code
<<
(and next lines) are already outside the function body. Could you please check whether it is a "copy-paste" error, or a mistake in the source code. At this moment it is difficult to say what's wrong. :-)
Cheers,
Zbyszek