Error finding primes with simple python program [on hold]

The below code is to output an array containing all the primes up to a limit. My code above does not do so, I cannot determine where the error is.

#generate prime numbers up to a given value
pa=[2]
limit=13
k=2
while k<limit:
    for i in pa:
        if k%i==0:
            k+=1
        else:
            pa.append(k)
            k+=1
print pa