Help with Mips assembly language

[byronflds]

I am trying to do a simple for loop that computes sum of a certain number of integers and then outputs the sum.

	.text
	.globl	main
main:
	li $9, 0
	li $10, 0
	li $11, 10
	li $12, 0
	li $13, 0

loop:
	bge $12 $11 exit
	li $v0, 4
	la $a0, msg
	syscall
	li $v0, 5
	syscall
	move $9, $v0
	add $10 $10 $9
	addi $12 $12 1
	li $v0, 4		# output msg2
	la $a0, msg2
	syscall
	li $v0,1		# output sum
	move $a0, $10
	syscall

	.data
msg:	.asciiz	"\nEnter an integer:   "
msg2:	.asciiz	"\nSum:   "

There error I keep getting is on the line with the branch

Instruction references undefined symbol at 0x0040003c [0x0040003c] 0x10200000 beq $1, $0, 0 [exit-0x00400038]

[byronflds]

thought it might be because I didnt add j loop to the end of the loop but that didnt fix the problem