Help please - first programme won't assemble

I have been attempting to assemble my first programme based on one taken from a book. After some work, I have been able to eliminate all of the errors but one. Here is an extract from the .LST file generated after a programme was assembled.

The PIC is the 16F84.

0001 0185 00021 Init clrf porta ; resets inputs & outputs
0002 0186 00022 clrf portb ; ditto
00023
0003 1683 00024 BSF STATUS ,5 ;selects BANK 1
0004 3000 00025 MOVLW 00 ;W = 00
0005 0085 00026 MOVWF PORTA ;SET RA0:4 O/P
0006 301F 00027 MOVLW 1F ;W = 1F
0007 0086 00028 MOVWF PORTB ;SET RB0:7 AS I/P
00029
0008 3007 00030 movlw b'00000111' ;sets up timing reg
Message[302]: Register in operand not in bank 0. Ensure that bank bits are correct.
0009 0081 00031 movwf OPTION_REG ;
00032
000A 1283 00033 bcf STATUS,5 ;selects bank 0
000B 018B 00034 clrf INTCON ;clears interrupts file reg

Can someone please tell me what is wrong. As far as I can see, I selected Bank1 at 00024. So why the error?

Len

It's not an error, it's just a warning, consult the MPASM helpfile for details, particularly the ErrorLevel directive which you can use to prevent the message.