Booth's Algorithm in MIPS

I have been work on this program, but I am having problems in rectifying the errors. Help me..text

Code:

* 12 bits register
* 8 bits anwer
* 4 bits multiplier and multiplicant
* user must enter multiplier and multiplicant
* print the results in both decimal and binary 

	.globl main
main:
	
	
		li $v0, 4	#Enter multiplicant	
		la $a0, msg1
		syscall
		li $v0, 5
		syscall
		move $a0, $v0


		li $v0, 4	#Enter multiplier
		la $a0, msg2
		syscall
		li $v0, 5
		syscall
		move $a1, $v0

		
		li $v0, 0 
		li $t1, 0 
		li $t0, 12 	# twelve bits 


algorithm:
		and $t2, $a0, 24 #24 bit mask
		sll $t2, $t2, 1
		or $t2, $t2, $t1 
		beq $t2, 2, check10 
		beq $t2, 1, check01 
		b shift 

check10: 	sub $v0, $v0, $a1 
		b shift

check01: 	add $v0, $v0, $a1

shift:
		and $t1, $a0, 16 #16 bit mask
		and $t2, $v0, 8  #8 bit mas
		sll $t2, $t2, 31
		srl $a0, $a0, 1 
		or $a0, $a0, $t2 
		sra $v0, $v0, 1 
		sub $t0,$t0, 1 
		bnez $t0, algorithm



		# Printing the 8 bits results ($v0,$a0)
		li		$v0, 4		
		la		$a0, msg3
		syscall
		li		$v0,1		
		move		$v0, $a0
		syscall


.data
	msg1: .asciiz"\nEnter multiplicand"
	msg2: .asciiz"\nEnter multiplier"
	msg3: .asciiz"\nThe Eight bits result is"