Write a JavaScript program to swap pairs of adjacent digits of a given integer of even length

function swap_adjacent_digits(n)
{
   if (n.toString().length%2!=0)
     {
       return false;
     }
  var result = 0,
		x = 1;
	while (n != 0) {
		var dg1 = n % 10,
			dg2 = ((n - dg1) / 10) % 10;
		result += x * (10 * dg1 + dg2);
		n = Math.floor(n / 100);
		x *= 100;
	}
	return result;
}
console.log(swap_adjacent_digits(15));
console.log(swap_adjacent_digits(1234));
console.log(swap_adjacent_digits(123456));
console.log(swap_adjacent_digits(12345));