How to make screen operation NG while displaying a message

Hi, Mx Expert   I want to gray out the screen while the message box is displayed so that no operation is accepted. Would you please teach me how to achieve this? Below is the current screen. (Background does not gray out) If you press a button on the above screen, a new message will appear.   2021/11/1 supplement I will tell you more detailed events. This event occurs when the row of DataGrid is not selected. What I would like you to teach is how to control multiple selections with DataGrid standard control errors (row unselected, row multiple selection, etc.). ⇒ Is it possible to edit the genuine error of DataGrid?
1 answers

Make the popup page Modal.

Start with the current popup page and either find or make a page layout that is a modal popup (you’ll find the Modal option in the layout type of the page layout.  Use the modal page layout instead of the current layout being used by the popup page.