Unable to process powershell function with content from windows form

Question

function CalendarShare {
    Add-MailboxFolderPermission -Identity ${FromUser.Text} -AccessRights Editor -User ${ToUser.Text}
}

When the program is run

Answer 1

Note: This is assuming that both $FromUser and $ToUser are textboxes

You aren't using your variable correctly for the identity parameter, should be:

function CalendarShare {
    Add-MailboxFolderPermission -Identity $FromUser.Text -AccessRights Editor -User $ToUser.Text}
}