My x86 bootloader is not working (not showing BIOS int 0x10h text)!

Here is the code. From what I have garnered, it should work perfectly fine:

BITS 16
ORG 0XC700:0000
PUSH EBP

INIT:

MOV AL, 0X03F
MOV EX, 0X0B3
XOR AL, EBP
CMP [AL], EX
POP EBP
JNE DOSERV

DOSERV:

PUSHA
CMP AL, [EX]
JZ SCREENWRITE

SCREENWRITE:

MOV AH, 03H
MOV SI, MSG
INT 0x10H;

MSG DB 'This is video memory on the screen using BIOS!!!!!', 0

times 510-($-$$)
DW 0xAAFF

Is there anything I wrote wrong (syntax error) or maybe data moved through wrong registers? Thanks in advance!

- Andy