tks bác, tuy nhiên vẫn chưa post bài dc. Khó post lắm, thường bị cái nầy nhất nè..

Server Error in '/' Application.
Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below

Đã thử nhiều chương trinh lướt web rùi, vẫn thế