Problem to store encrypted data in database using asp.net

I am trying to store encrypted data in database. It stores correctly when i execute the query in sql server  like

CREATE TABLE login_details(uid integer,username varchar(10),password varbinary(100))
INSERT INTO  login_details(uid,username,password) VALUES(1,'smith',EncryptByPassPhrase('12','XXX'))
INSERT INTO  login_details(uid,username,password) VALUES(2,'kennal',EncryptByPassPhrase('12','YYY'))
INSERT INTO  login_details(uid,username,password) VALUES(3,'staurt',EncryptByPassPhrase('12','ZZZ'))
INSERT INTO  login_details(uid,username,password) VALUES(4,'bHARAT',EncryptByPassPhrase('12','BHARAT'))

But when i store using asp.net it create a problem. It stores only 1 character in database for eg: if i want to store

"hello" , it stores only first character 'h' not full string. below i am giving you  my complete code

html code

C# code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Collections;
using System.Globalization;
public partial class passwordencryption : System.Web.UI.Page
{
    SqlConnection con = new SqlConnection();
    SqlCommand cmd;
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btn_submit_Click(object sender, EventArgs e)
    {
        con.ConnectionString = ConfigurationManager.ConnectionStrings["cnn"].ConnectionString;
        con.Open();


        SqlCommand cmd = new SqlCommand();
       // cmd.CommandText = "insert into login_details values(@uid,@username,(EncryptByPassPhrase @password))";
       // cmd.CommandText = " INSERT INTO  login_details  VALUES(@uid,@username,EncryptByPassPhrase('12',@password))";
       // cmd.CommandType = CommandType.Text;
        cmd.CommandText = "INSERT INTO  login_details(uid,username,password) VALUES(@uid,@username,EncryptByPassPhrase('12',@password))";
        cmd.Connection = con;
        cmd.Parameters.AddWithValue("@uid", txt_uid.Text);
        cmd.Parameters.AddWithValue("@username", txt_uname.Text);
        cmd.Parameters.AddWithValue("@password", upass.Text);
        cmd.ExecuteNonQuery();
        cmd.Dispose();
        con.Close();
      //  bind_lbl();
    }
}

table login_detail

columnname             datatype

uid                               int

username                    varchar(100)