Azure shutdown with user prompt

Hi 

I am trying to configure a process with our azure VMs. I would like to shutdown/deallocate the servers on a schedule, this is well documented using tags etc. and I have it working. I would however, like to do prompt logged on users with an option to cancel the shutdown. If they do not cancel the VM should be shutdown and deallocated

I have been thinking the best way to do this is to

1. Send a remote PowerShell to initiate a shutdown (allowing the user to cancel if this is possible)
2. Deallocate the server if the tag is correct and the server is already shutdown (i.e. has not been cancelled by the user in step 1)

Any guidance on this would be great, is this the best option? I am using the AutoShutdownSchedule Runbook in azure.

Thanks

Michael