Connecting silverlight application to MySQL database

I have tried using WCF Data services.... The tutorial however only showed how to retrieve data from the database and display in a grid. I know that you attach a .svc file to the project which holds all the database connection details and methods that bring back data but i can't figure out how to add more methods to the .svc file and call them from the app....

This is the code with the method to retrieve from the database:

//namespace SilverlightWcfService
namespace SilverlightWCFTutorial.Web
{
// NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "DatabaseService" in code, svc and config file together.
public class DatabaseService : IDatabaseService
{
string myConnectionString = "server=localhost; user id=root; password=password; database=silverlight1";
//string myConnectionString = "someConnectionString";
public string GetData(int value)
{
return string.Format("You entered {0}", value);
}
public List<string> GetNames()
{
List<string> list = new List<string>();
List<string> list2 = new List<string>();

using (MySqlConnection cn = new MySqlConnection(myConnectionString))
{


using (MySqlCommand cmd = cn.CreateCommand())
{
cmd.CommandText = "SELECT ID, FirstName, lastName, Age FROM person";
cmd.CommandType = CommandType.Text;

cn.Open();

using (MySqlDataReader dr = cmd.ExecuteReader())
{
string id;
string fname = null;
string lname = null;
string age;
while (dr.Read())
{
id = dr["ID"].ToString();
fname = dr["FirstName"].ToString();
lname = dr["LastName"].ToString();
age = dr["Age"].ToString();
list.Add(id);//(dr.GetString(0));
list2.Add(fname);
list.Add(lname);
list.Add(age);
}
}
}
}

return list;
}
}
}

===============================================================

How do i add another method to update or add information to the same database?... I am not sure as to where to place the code in this .svc file...