If you use MPASM as assembler try...
Code:
    @ __CONFIG _INTRC_OSC_NOCLKOUT & _WDT_ON & _PWRTE_ON & _MCLRE_OFF & _LVP_OFF & _BODEN_ON 
         ' Internal Oscillator
         ' Enable watch dog timer
         ' Enable power up timer
         ' Disable MCLR pin
         ' Disable low voltage programming
         ' Enable brown out detect
if you use PM as assembler, look and try all the suggestion in the FAQ section. There's a full thread wich discuss of HOW TO.

here it is => http://www.picbasic.co.uk/forum/showthread.php?t=543