function to perform swapping in an array - mips

Question

The basic flow of the program is as follows:
1. Print the original content of array.
2. Ask the user for two indices X and Y.
3. Swap the two elements if Array[X] > Array[Y].
4. Print the modified array only if swapping occurs.
.data
array: .word 8, 2, 1, 6, 9, 7, 3, 5, 0, 4
newl: .asciiz "\n"
.text
la $a0, array
li $a1, 10
jal printArray
#Ask the user for two indices
li $v0, 5 #System call code for read_int
syscall
addi $t0, $v0, 0 # first user input in $t0
li $v0, 5 #System call code for read_int
syscall
addi $t1, $v0, 0 # second user input in $t1
swap : li $a1, 0 #inx1
li $a2, 0 #inx2
sll $t0, $a1, 2 # $t0 = inx1* 4
add $t0, $t0, $a0 # $t0 is the address of A[$a1]
sll $t3, $a2, 2 # $t3 = inx2* 4
add $t3, $t3, $a0 # $t3 is the address of A[$a2]
lw $t1, 0($t0) # $t1 = A[$a1]
lw $t2, 0($t3) # $t2 = A[$a2]
ble $t1, $t2, noPrint# if A[$a1] <=A[$a2] goto noPrint
sw $t1, 0($t3) # do the swap
sw $t2, 0($t0) # do the swap
syscall
jal printArray
printArray:
addi $t1, $a0, 0 #$t1 is the pointer to the item
sll $t2, $a1, 2 #$t2 is the offset beyond the last item
add $t2, $a0, $t2 #$t2 is pointing beyond the last item
loop: beq $t1, $t2, end
lw $t3, 0($t1) #$t3 is the current item
li $v0, 1 # system call code for print_int
addi $a0, $t3, 0 # integer to print
syscall # print it
addi $t1, $t1, 4
j loop # Another iteration
end:
li $v0, 4 # system call code for print_string
la $a0, newl #
syscall # print newline
jr $ra # return from this function
noPrint:
li $v0, 10 # system call code for exit
syscall # terminate program
I'm having problems with swap function. It doesn't print anything on console window(using QtSpim). Can you please recommend any suggestion?