public bool add(string Username, string Pasword)
{
     string myconnection = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\HUZAI\OneDrive\Documents\Visual Studio 2013\Projects\APFinal Practise\APFinal Practise\App_Data\users.mdb";

     using (OleDbConnection con=new OleDbConnection(myconnection))
     {
         OleDbCommand cmd = new OleDbCommand("UPDATE users SET password = @pass WHERE username = @name", con);
         cmd.Parameters.AddWithValue("pass", Password);
         cmd.Parameters.AddWithValue("Name", name);

         if(cmd.ExecuteNonQuery() > 0)
         {
             return true;
         }

         return false;
    }
}