javascript algorithms and data structures interview questions

1
2function isPrime(n)
3{
4  var divisor = 3, 
5      limit = Math.sqrt(n);
6  
7  //check simple cases
8  if (n == 2 || n == 3)
9     return true;
10  if (n % 2 == 0)
11     return false;
12
13  while (divisor <= limit)
14  {
15    if (n % divisor == 0)
16      return false;
17    else
18      divisor += 2;
19  }
20  return true;
21}
22
23> isPrime(137);
24  = true
25> isPrime(237);
26  = false
27