first message on line 2, your program should be like this:

CALL CLEAR_LCD
MOV DPTR,#msg1_address ; your first message
MOV A, #C0; initialize the cursor to line 2 (#C0, if I recall)
CALL SHOW_MSG

second message:

CALL CLEAR_LCD
MOV DPTR,#msg1_address ; your first message
MOV A, #80; initialize the cursor to line 1 (#80, if I recall)
MOV DPTR,#msg2_address ; your 2nd message
MOV A, #C0; initialize the cursor to line 2 (#C0, if I recall)
CALL SHOW_MSG

third message:

CALL CLEAR_LCD
MOV DPTR,#msg2_address ; your 2nd message
MOV A, #80; initialize the cursor to line 1 (#80, if I recall)
MOV DPTR,#msg3_address ; your 3rd message
MOV A, #C0; initialize the cursor to line 2 (#C0, if I recall)
CALL SHOW_MSG

and goes on, as you need. I think that you got the spirit.

orlando