How can I insert data in three tables which are Customer, Company and Cust_Comp which is the the linking table of the first two tables using stored procedure

USE [pastel]
GO
/****** Object:  StoredProcedure [dbo].[AddCustomer]    Script Date: 8/28/2015 9:59:06 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[AddCustomer]
@CompanyName nvarchar(50),
@RegistrationNo nvarchar(50),
@CompanyTelephoneNo nvarchar(50),
@BuildingName nvarchar(50),
@CompanyTown nvarchar(50),
@Town nvarchar(50),
@CopmanyCity nvarchar(50),
@City nvarchar(50),
@CompanyPostalCode nvarchar(50),
@Country nvarchar(50),
@TelephoneNo nvarchar(50),
@CompanyStreet nvarchar(50),
@YearsInBusiness nvarchar(50),
@Street nvarchar(50),
@CompanyLogo varbinary(max),
@EmailAddress nvarchar(50),
@CompanyWebsite nvarchar(50),
@BankName nvarchar(50),
@AccountNo nvarchar(50),
@BranchCode nvarchar(50),
@Status int,
@PostalCode nvarchar (50),
@FirstName nvarchar(50),
@LastName nvarchar(50),
@DateOfBirth date,
@CellNo nvarchar(50),
@Gender nvarchar(50),
@IDNo nvarchar(50),
@Nationality nvarchar(50),
@Race nvarchar(50)


As

declare @CompanyID int
declare @CustomerID int

INSERT INTO COMPANY
(CompanyName, RegistrationNo,CompanyTelephoneNo, BuildingName, CompanyStreet,CompanyTown,CompanyCity,CompanyPostalCode,Country,YearsInBusiness,CompanyLogo,EmailAddress,CompanyWebsite,BankName,AccountNo,BranchCode,[Status])
VALUES
(@CompanyName,@RegistrationNo,@CompanyTelephoneNo,@BuildingName, @CompanyStreet,@CompanyTown,@CopmanyCity,@PostalCode,@Country,@YearsInBusiness,@CompanyLogo,@EmailAddress,@CompanyWebsite,@BankName,@AccountNo,@BranchCode,@Status);

Set @CompanyID=SCOPE_IDENTITY()



INSERT INTO CUSTOMER

(FirstName,LastName,DateOfBirth,Gender,IDNo,Nationality,Race,Country,City,Town,Street,PostalCode,TelephoneNo,[CellNo],Email)
VALUES(@FirstName,@LastName,@DateOfBirth,@Gender,@IDNo,@Nationality,@Race,@Country,@City,@Town,@Street,@PostalCode,@TelephoneNo,@CellNo,@EmailAddress);

Set @CustomerID= SCOPE_IDENTITY()



INSERT INTO CUST_COMP
    (CustomerID,CompanyID)
    VALUES(@CustomerID,@CompanyID)

 private void AddCustCompany(string FirstName, string LastName, string CellNo, string EmailAddress, string CompanyName, string BuildingName, string CompanyCity, string CompanyStreet, string CompanyTown,
            string CompanyPostalCode, string CompanyTelephoneNo, string Country, string CompanyWebsite, string RegistrationNo, byte[] CompanyLogo, string City, string Street, string Town, string TelephoneNo,DateTime DateOfBirth)
        {

            using (SqlConnection dbConn = new SqlConnection(connString))
            {
                dbConn.Open();

                SqlCommand dbCmd = new SqlCommand("AddCustomer", dbConn);
                dbCmd.CommandType = CommandType.StoredProcedure;

                dbCmd.Parameters.AddWithValue("@FirstName", SqlDbType.NVarChar).Value = FirstName;
                dbCmd.Parameters.AddWithValue("@LastName", SqlDbType.NVarChar).Value = LastName;
                dbCmd.Parameters.AddWithValue("@CellNo", SqlDbType.NVarChar).Value = CellNo;
                dbCmd.Parameters.AddWithValue("@EmailAddress", SqlDbType.NVarChar).Value = EmailAddress;
                dbCmd.Parameters.AddWithValue("@CompanyName", SqlDbType.NVarChar).Value = CompanyName;
                dbCmd.Parameters.AddWithValue("@BuildingName", SqlDbType.NVarChar).Value = BuildingName;
                dbCmd.Parameters.AddWithValue("@CompanyCity", SqlDbType.NVarChar).Value = CompanyCity;
                dbCmd.Parameters.AddWithValue("@CompanyStreet", SqlDbType.NVarChar).Value = CompanyStreet;
                dbCmd.Parameters.AddWithValue("@CompanyTown", SqlDbType.NVarChar).Value = CompanyTown;
                dbCmd.Parameters.AddWithValue("@CompanyPostalCode", SqlDbType.NVarChar).Value = CompanyPostalCode;
                dbCmd.Parameters.AddWithValue("@CompanyTelephoneNo", SqlDbType.NVarChar).Value = CompanyTelephoneNo;
                dbCmd.Parameters.AddWithValue("@Country", SqlDbType.NVarChar).Value = Country;
                dbCmd.Parameters.AddWithValue("@CompanyWebsite", SqlDbType.NVarChar).Value = CompanyWebsite;
                dbCmd.Parameters.AddWithValue("@RegistrationNo", SqlDbType.NVarChar).Value = RegistrationNo;
                dbCmd.Parameters.AddWithValue("@Town", SqlDbType.NVarChar).Value = Town;
                dbCmd.Parameters.AddWithValue("@City", SqlDbType.NVarChar).Value = City;
                dbCmd.Parameters.AddWithValue("@Streeet", SqlDbType.NVarChar).Value = Street;
                dbCmd.Parameters.AddWithValue("@TelephoneNo", SqlDbType.NVarChar).Value = TelephoneNo;
                dbCmd.Parameters.AddWithValue("@DateOfBirth", SqlDbType.Date).Value = DateOfBirth;
     
                dbCmd.Parameters.AddWithValue("@CompanyLogo", SqlDbType.VarBinary).Value = CompanyLogo;



                int i = dbCmd.ExecuteNonQuery();

                dbConn.Close();


            }
        }


        protected void btnCreateCustomer_Click(object sender, EventArgs e)
        {
            if (FileUpload1.HasFile)
            {
                FileUpload img = (FileUpload)FileUpload1;
                Byte[] imgByte = null;
                if (img.HasFile && img.PostedFile != null)
                {
                    // Posted Image
                    HttpPostedFile File = FileUpload1.PostedFile;
                   
                    imgByte = new Byte[File.ContentLength];
                 
                    File.InputStream.Read(imgByte, 0, File.ContentLength);


                }
                string FirstName = txtFirstName.Text;
                string LastName = txtLastName.Text;
                string CellNo = txtCellNumber.Text;
                string EmailAddress = txtEmail.Text;
                string City = txtCity.Text;
                string Street = txtStreet.Text;
                string Town = txtTown.Text;
                string TelephoneNo = txtTelephoneNo.Text;
                DateTime DateOfBirth;
                if (DateTime.TryParseExact(TxtDob.Text,"yyyy-MM-dd:0", null, DateTimeStyles.None, out DateOfBirth))

{
 
 
}
                {

                    lblMessageDate.Text = ("date and year  is incorrect");
                }
                // EncryptPassword encrypt = new EncryptPassword();
                //GeneratePassword pass = new GeneratePassword();
                string CompanyName = txtCompanyName.Text;
                string BuildingName = txtBuildingName.Text;
                string CompanyCity = txtCompCity.Text;
                string CompanyStreet = txtStreetName.Text;
                string CompanyTown = txtTown.Text;
                string CompanyPostalCode = txtCompPostalCode.Text;
                string CompanyTelephoneNo = txtPhoneNumber.Text;
                string Country = DropDownList1.SelectedValue;
                string CompanyWebsite = txtCompWebsite.Text;
                string RegistrationNo = txtRegistrationNo.Text;
               


                byte[] CompanyLogo = FileUpload1.FileBytes;

                AddCustCompany( FirstName, LastName, CellNo, EmailAddress,CompanyName,BuildingName,CompanyCity, CompanyStreet, CompanyTown, CompanyPostalCode, CompanyTelephoneNo,Country,CompanyWebsite, RegistrationNo,  CompanyLogo, City, Street, Town, TelephoneNo, DateOfBirth);

            }
        }
    }