[Serializable]
public struct UserInfo{
public string username;
public string password;
};

 [WebMethod]
public UserInfo GetAUserByID(string username)
{
UserInfo ui = new UserInfo();
string sql = "select username,password from UserInfo where username='";
sql += username;
sql += "'";
try
{
sqlConnection.Open();
//SQLCMD.CommandText = sql;
                SqlDataAdapter adapter = new SqlDataAdapter(sql,sqlConnection);
//adapter = SQLCMD.ExecuteReader();
                DataSet ds = new DataSet();
adapter.Fill(ds);
ui.username = ds.Tables[0].Rows[0]["username"].ToString();
ui.password = ds.Tables[0].Rows[0]["password"].ToString();
//sda.
            }
catch { }
finally
{
sqlConnection.Close();
}
return ui;
}