Hello and thank you for taking a moment to read this message. Here is my code:
SqlConnection dbConn2 = new SqlConnection(Session["usersconn"].ToString());

SqlCommand sqlCom2 = new SqlCommand("Update tblUser SET DiamondDealerID=@DiamondDealerID", dbConn2);

sqlCom2.Parameters["@DiamondDealerID"].Direction = ParameterDirection.Input;
sqlCom2.Parameters.Add("@DiamondDealerID", SqlDbType.Varchar);

sqlCom2.Parameter["@DiamonDealerId"].Value=DateTime.Now.Year.ToString()+Session["companyid"]+intID ;

dbConn2.Open();
sqlCom2.ExecuteNonQuery();
dbConn2.Close();

I am getting the following error
Must declare the variable '@DiamondDealerID'.

Any help you could provide would be greatly appreciated.