password encryption using Salt and Hash technique

I tried encrypting my password field as shown in this post. https://stackoverflow.com/questions/883371/effective-password-encryption

What I am trying to is generate random salt for every password and then encrypt it using Hashing algorithm. I tried the code shown in the post. But I am getting error. 

public string Encrypt(string clearText)
        {
            try
            {
                byte[] passwordHash = ComputeHash(clearText);
                byte[] salt = GetRandomSalt();
                byte[] saltHash = ComputeHash(salt.ToString());

                byte[] hashWithSaltBytes = new byte[hashBytes.Length + saltBytes.Length];
                for (int i = 0; i < hashBytes.Length; i++)
                    hashWithSaltBytes[i] = hashBytes[i];
                for (int i = 0; i < saltBytes.Length; i++)
                    hashWithSaltBytes[hashBytes.Length + i] = saltBytes[i];

                string hashValue = Convert.ToBase64String(hashWithSaltBytes);

                return hashValue;
            }
            catch (Exception)
            {

                throw;
            }
        }

//random salt generation
public static byte[] GetRandomSalt()
{
	int minSaltSize = 16;
	int maxSaltSize = 32;

	Random random = new Random();
	int saltSize = random.Next(minSaltSize, maxSaltSize);
	saltBytes = new byte[saltSize];
	RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
	rng.GetNonZeroBytes(saltBytes);
	return saltBytes;
}
// hashing
public static byte[] ComputeHash(string plainText)
{
	byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
	HashAlgorithm hash = new SHA256Managed();
	return hash.ComputeHash(plainTextWithSaltBytes);
}

For the method Encrypt I am getting error The name 'hashBytes' does not exist in the current context and in the methodComputeHash I am getting the error The name 'plainTextWithSaltBytes' does not exist in the current context. How can I solve this?