Sieve Of Eratosthenes

sieve.js

function sieve(max) {
  var D = [], primes = [];
  for (var q=2; q<max; q++) {
  	if (D[q]) {
  		for (var i=0; i<D[q].length; i++) {
  			 var p = D[q][i];
  			 if (D[p+q]) D[p+q].push(p);
  			 else D[p+q]=[p];
  		}
  		delete D[q];
  	} else {
  		primes.push(q);
  		if (q*q<max) D[q*q]=[q];
  	}
  }
  return primes;
}
sieve(100)

Returns prime numbers.