Extension method that creates a random negative or positive value

RandomHelper.cs

using System;

namespace GenerateLatLon.Helpers
{
    public static class RandomHelper
    {
        public static int NegativePositive(this Random r)
        {
            int iNum;

            iNum = r.Next(-30, 50); //put whatever range you want in here from negative to positive 
            if (iNum == 0)
            {
                iNum++; //to avoid divide by zero
            }

            return iNum / (int)Math.Abs(iNum);
        }
    }
}