inserting a value into the sql db, error at cmd.executenonquery

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;

public partial class _Default : System.Web.UI.Page
{
    SqlConnection con = new SqlConnection("Data Source=JIMMY-PC;initial Catalog=jimmy;Integrated Security=true");
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        using(SqlCommand cmd = new SqlCommand("Insert into Emplo ([Name],[Designation],[Dept],[D O B],[Sex],[Address]) values (@Name,@des,@dept,@DOB,@Sex,@Address)", con))
        {
            cmd.Parameters.Add("@Name", SqlDbType.VarChar).Value = TextBox1.Text;
            cmd.Parameters.Add("@des", SqlDbType.VarChar).Value = TextBox2.Text;
            cmd.Parameters.Add("@dept", SqlDbType.VarChar).Value = TextBox3.Text;
            cmd.Parameters.Add("@DOB", SqlDbType.SmallDateTime).Value = TextBox4.Text;
            cmd.Parameters.Add("@Sex", SqlDbType.VarChar).Value = RadioButton1.SelectedItem.Text;
            cmd.Parameters.Add("@Address", SqlDbType.VarChar).Value = TextBox5.Text;
            con.Open();
            cmd.ExecuteNonQuery();
            Response.Write("<script>alert('Registered successfully......!')</script>");
        }
        //string c=CreateRandomPassword();
        using (SqlCommand cmd = new SqlCommand("insert into Emplo([Password]) values (@pass)", con))
        {
            cmd.Parameters.Add("@pass", SqlDbType.VarChar).Value = CreateRandomPassword(6);
            cmd.ExecuteNonQuery();
        }
    con.Close();
    }

    public static string CreateRandomPassword(int PasswordLength)
        { 
        string allowdChars = "0123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ";
        Random randNum = new Random();
        char[] chars = new char[PasswordLength];
        int allowedCharCount = allowdChars.Length;
        for (int j = 0; j < PasswordLength; j++)
        {
            chars[j] = allowdChars[(int)((allowdChars.Length) * randNum.NextDouble())];
        }
         return new string(chars);       
        }
}