Encryption and Decryption in javascript and c#

javascript
<script src="http://crypto-js.googlecode.com/svn/tags/3.1.2/build/rollups/aes.js "></script>
    <script type="text/javascript">

        function SubmitsEncry() {

            debugger;
            var txtUserName = "Please enter UserName";

            var key = CryptoJS.enc.Utf8.parse('8080808080808080');
            var iv = CryptoJS.enc.Utf8.parse('8080808080808080');

            var encrypted = CryptoJS.AES.encrypt(CryptoJS.enc.Utf8.parse(txtUserName), key,
            {
                keySize: 128 / 8,
                iv: iv,
                mode: CryptoJS.mode.CBC,
                padding: CryptoJS.pad.Pkcs7
            });
            var decrypted = CryptoJS.AES.decrypt(encrypted, key,
               {
                   keySize: 128 / 8,
                   iv: iv,
                   mode: CryptoJS.mode.CBC,
                   padding: CryptoJS.pad.Pkcs7
               });
            alert(decrypted.toString(CryptoJS.enc.Utf8));
        }
        SubmitsEncry();

    </script>

c#

 public ActionResult Index()
        {
            string s = "The brown fox jumped over the green frog";
            //string k = "urieurut";
            var encry = EncryptStringAES(s);
            var sss = DecryptStringAES(encry);
            return View();
        }
        public static string DecryptStringAES(string cipherText)
        {
            var keybytes = Encoding.UTF8.GetBytes("8080808080808080");
            var iv = Encoding.UTF8.GetBytes("8080808080808080");

            var encrypted = Convert.FromBase64String(cipherText);
            var decriptedFromJavascript = DecryptStringFromBytes(encrypted, keybytes, iv);
            return string.Format(decriptedFromJavascript);
        } 
        private static string DecryptStringFromBytes(byte[] cipherText, byte[] key, byte[] iv)
        {
            // Check arguments.  
            if (cipherText == null || cipherText.Length <= 0)
            {
                throw new ArgumentNullException("cipherText");
            }
            if (key == null || key.Length <= 0)
            {
                throw new ArgumentNullException("key");
            }
            if (iv == null || iv.Length <= 0)
            {
                throw new ArgumentNullException("key");
            }

            // Declare the string used to hold  
            // the decrypted text.  
            string plaintext = null;

            // Create an RijndaelManaged object  
            // with the specified key and IV.  
            using (var rijAlg = new RijndaelManaged())
            {
                //Settings  
                rijAlg.Mode = CipherMode.CBC;
                rijAlg.Padding = PaddingMode.PKCS7;
                rijAlg.FeedbackSize = 128;

                rijAlg.Key = key;
                rijAlg.IV = iv;

                // Create a decrytor to perform the stream transform.  
                var decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

                try
                {
                    // Create the streams used for decryption.  
                    using (var msDecrypt = new MemoryStream(cipherText))
                    {
                        using (var csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                        {

                            using (var srDecrypt = new StreamReader(csDecrypt))
                            {
                                // Read the decrypted bytes from the decrypting stream  
                                // and place them in a string.  
                                plaintext = srDecrypt.ReadToEnd();

                            }

                        }
                    }
                }
                catch
                {
                    plaintext = "keyError";
                }
            }

            return plaintext;
        }

        public static string EncryptStringAES(string plainText)
        {
            var keybytes = Encoding.UTF8.GetBytes("8080808080808080");
            var iv = Encoding.UTF8.GetBytes("8080808080808080");

            var encryoFromJavascript = EncryptStringToBytes(plainText, keybytes, iv);
            return Convert.ToBase64String(encryoFromJavascript);
        }  


        private static byte[] EncryptStringToBytes(string plainText, byte[] key, byte[] iv)
        {
            // Check arguments.  
            if (plainText == null || plainText.Length <= 0)
            {
                throw new ArgumentNullException("plainText");
            }
            if (key == null || key.Length <= 0)
            {
                throw new ArgumentNullException("key");
            }
            if (iv == null || iv.Length <= 0)
            {
                throw new ArgumentNullException("key");
            }
            byte[] encrypted;
            // Create a RijndaelManaged object  
            // with the specified key and IV.  
            using (var rijAlg = new RijndaelManaged())
            {
                rijAlg.Mode = CipherMode.CBC;
                rijAlg.Padding = PaddingMode.PKCS7;
                rijAlg.FeedbackSize = 128;

                rijAlg.Key = key;
                rijAlg.IV = iv;

                // Create a decrytor to perform the stream transform.  
                var encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

                // Create the streams used for encryption.  
                using (var msEncrypt = new MemoryStream())
                {
                    using (var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                    {
                        using (var swEncrypt = new StreamWriter(csEncrypt))
                        {
                            //Write all data to the stream.  
                            swEncrypt.Write(plainText);
                        }
                        encrypted = msEncrypt.ToArray();
                    }
                }
            }
            // Return the encrypted bytes from the memory stream.  
            return encrypted;
        }