Failed To Convert Parameter Value From A String To A Int32.(stored Procedures)

i had writen a stored procedure for inserting vlaues frma form into sql but iam getting this error can any pls help me

Failed to convert parameter value from a String to a Int32

my stored procedureALTER PROCEDURE sp_addcustomer



(@customerid as int,

@fname as char(10),@lname as char(10) ,

@companyname as char(10),@email as nvarchar(50),

@address as char(10),@city as char(10),

@zip as char(10),@country as char(10),

@phone as nvarchar(50),@state as char(10)

)



ASinsert into customer(customerid ,fname ,lname ,companyname, email , address ,city,zip,country,phone,state)

values(@customerid ,@fname ,@lname ,@companyname,@email,@address,@city,@zip,@country,@phone,@state)

RETURN

 

CODE IN C# IS

 SqlConnection cn = new SqlConnection(Session["conn"].ToString());

cn.Open();SqlCommand cmd = new SqlCommand();

cmd.Connection = cn;cmd.CommandType = CommandType.StoredProcedure;cmd.CommandText = "sp_addcustomer";

 

//SqlParameter p1, p2, p3, p4, p5, p6, p7, p8, p9, p10,p11;cmd.Parameters.Add(new SqlParameter("@customerid",SqlDbType.Int));

cmd.Parameters["@customerid"].Value =CustomerID.Text;cmd.Parameters.Add(new SqlParameter("@fname", SqlDbType.Char));

cmd.Parameters["@fname"].Value = fname.Text;cmd.Parameters.Add(new SqlParameter("@lname", SqlDbType.Char));

cmd.Parameters["@lname"].Value = lname.Text;cmd.Parameters.Add(new SqlParameter("@companyname", SqlDbType.Char));

cmd.Parameters["@companyname"].Value = companyname.Text;cmd.Parameters.Add(new SqlParameter("@email", SqlDbType.NVarChar));

cmd.Parameters["@email"].Value = email.Text;cmd.Parameters.Add(new SqlParameter("@address", SqlDbType.Char));

cmd.Parameters["@address"].Value = address.Text;cmd.Parameters.Add(new SqlParameter("@city", SqlDbType.Char));

cmd.Parameters["@city"].Value = city.Text;cmd.Parameters.Add(new SqlParameter("@zip", SqlDbType.NVarChar));

cmd.Parameters["@zip"].Value = zip.Text;cmd.Parameters.Add(new SqlParameter("@country", SqlDbType.Char));

cmd.Parameters["@country"].Value = Country.Text;cmd.Parameters.Add(new SqlParameter("@phone", SqlDbType.NVarChar));

cmd.Parameters["@phone"].Value = Phone.Text;cmd.Parameters.Add(new SqlParameter("@state", SqlDbType.Char));cmd.Parameters["@state"].Value = state.Text;

cmd.ExecuteNonQuery();

cn.Close();

Response.Redirect("main.aspx?st=Employee added successfully");