On Sat, 25 Jul 2009 16:18:45 +0200 Csanyi Pal wrote: > What can I do to solve this problem? > Any advice will be appreciated! I'm suspecting you have a recent version of gcc (4.xx). These versions are more touchy about the #includes at the start of the program. strtol is part of stdlib.h which earlier was included by default (which only gcc did. Other compilers have always complained). I'd say the problem will go away if you add #include in that file (at the top somewhere). Mostly guessing - I had a similar problem a couple of days ago. John -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist