Query Close

Indicates whether the user has attempted to close an MS-DOS – based application from Windows by choosing the Close command from the system menu.

mov ah, 16h   ; Windows multiplex function 
mov al, 8Fh   ; VM Close 
mov dh, 1     ; Query Close 
mov dl, 0     ; always 0 
int 2Fh

Return Value

Returns one of the following values in the AX register:

0 The close command was chosen, and the application has not acknowledged the close state.
1 The close command was chosen, and the application has acknowledged the close state.
168Fh The close command has not been chosen, and the application should continue running.

Remarks

Query Close returns a nonzero value if the application has not enabled the Close command by using the Enable or Disable Close Command function.