How can I make my script stop when clicked on the cancel Button?

Dear Community
I am working on a script that gives you prompts for copying whole folderstructures including the ACLs (permissions)
My Question now is how can I make it so that when I click on the cancel button in the popup that it actually cancels?

Here is my code:

#----------------------Source Drive and Folder---------------------#
[System.Reflection.Assembly]::LoadWithPartialName('Microsoft.VisualBasic') | Out-Null
$sourceDrive = [Microsoft.VisualBasic.Interaction]::InputBox("Please enter the source drive for copying `n(e.g: C)", "source drive", "")
$sourceFolder = [Microsoft.VisualBasic.Interaction]::InputBox("Please enter the source folder for copying `n(e.g: Folder\Something)", "source folder", "")
#----------------------Source Drive and Folder---------------------#

#-------------------Destination Drive and Folder-------------------#
[System.Reflection.Assembly]::LoadWithPartialName('Microsoft.VisualBasic') | Out-Null
$destinationDrive = [Microsoft.VisualBasic.Interaction]::InputBox("Please enter the destination drive for copying `n(e.g: D)", "destination drive", "")
$destinationFolder = [Microsoft.VisualBasic.Interaction]::InputBox("Please enter the destination folder for copying `n(e.g: Folder1\Something2)", "destination folder", "")
#-------------------Destination Drive and Folder-------------------#

#--------------------Create new Folder for Copy--------------------#
$createNewFolder = [Microsoft.VisualBasic.Interaction]::InputBox("Do you want to create a new folder in this directory? `n(e.g: y/n)", "Create new folder", "")
if ($createNewFolder -eq "n") {
    xcopy "$sourceDrive:\$sourceFolder" "$destinationDrive:\$destinationFolder" /O /X /E /H /K
}
elseif ($createNewFolder -eq "y") {
    [System.Reflection.Assembly]::LoadWithPartialName('Microsoft.VisualBasic') | Out-Null
    $newFolder = [Microsoft.VisualBasic.Interaction]::InputBox("Please enter the name of the folder `n(e.g: somefolder)", "New folder", "")
    xcopy "$sourceDrive :\$sourceFolder" "$destinationDrive:\$newfolder\$destinationFolder" /O /X /E /H /K
}
else {

}
#--------------------Create new Folder for Copy--------------------#

#xcopy "$sourceDrive :\$sourceFolder" "$destinationDrive:\$destinationFolder" /O /X /E /H /K

This was posted in StackOverflow too: https://stackoverflow.com/questions/64659341/how-can-i-make-my-script-stop-when-clicked-on-the-cancel-button

Thanks in advance

Martin