[Ctrl+A Select all Note:Introducing external Js requires refreshing the page before execution]
The effect is as follows:
When empty, this selection prompt box will not appear.
But the problem arises again: If I hope the user can save user-related data when clicking the "OK" button to close the browser, then what should I do?
It seems that the only thing to use the onunload parameter is to use.
Modify the above code as follows:
[Ctrl+A Select all Note:Introducing external Js requires refreshing the page before execution]