About the ASP.net button button onclick and OnClientClick event _ Practical Tips

Generally we use OnClientClick to verify our submission data, but this must return ture or false, that is, must add returns, otherwise onclick failure. The onclick server-side event is aborted when you return false, and when your JS validation is faulty, you will also skip validation and execute the server-side event OnClientClick directly. To avoid such errors, you might consider using server-side validation so that you omit the OnClientClick event, and you don't have to consider the conflict with onclick.