How To Invoke Insert Stored Procedure

Feeling really dumb tonight - below is my stored procedure and code behind which completes (it puts "completed" in TextBox4) but does not insert anything into database.

Questions:
1) do in need to include the primary key field in the insert stored procedure?
2) do I need a DataAdapter to actually get it running and open and close the connection? 

STORED PROCEDURE running on SQL 2000 server: ______________________________________

CREATE PROCEDURE newuser003.InsertCompanyInfo

@CS_CompanyName nchar(100),
@CS_City nchar(500),
@CS_Phone varchar(20)

AS

INSERT into tblCompanyInfo_Submit
(CS_CompanyName, CS_City, CS_Phone)
VALUES ('@CS_CompanyName', '@CS_City', '@CS_Phone')
RETURN

C# CODE BEHIND: ______________________________________________________ 

public partial class ContractorSubmision : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {       }
    protected void Button1_Click(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["localhomeexpoConnectionString2"].ConnectionString);
        SqlCommand cmd = new SqlCommand("CompanyInfoSubmit", con);
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Parameters.AddWithValue("@CS_CompanyName", TextBox1.Text);
        cmd.Parameters.AddWithValue("@CS_City", TextBox2.Text);
        cmd.Parameters.AddWithValue("@CS_Phone", TextBox3.Text);
        TextBox4.Text = "Completed";
    }
}