elif syntax error

Question

i'm trying to write a simple program to check if the input number is prime or not and i'm already stuck with the basics
running this few lines generates a syntax error at the starting of elif line
usernum = int(input( 'please enter an integer : '))
for i in range(2,usernum-1) :
if usernum % i == 0 :
print ('your entery is not a prime number')
elif usernum == 1:
input('choose a number except 1 : ')
else :
print ('your entery is a prime number')