It would be very useful if it was possible to have a message box appear as part of a script that would not allow the script to proceed until the user acknowledges the message.

For example, a process that is currently running needs to be closed to proceed with the script. At present if a message box is displayed the script will display the message and then continue without the need for the user to acknowledge/interact with the message. This could well cause loss of work which could be avoided if the message that advises the user to save work and close the application would force the script to wait until the OK button was clicked or the timeout period of the message elapsed.