Several standard dialogs were added to Tk. These let you display alerts, prompt the user, choose colors, and select files using dialogs that are implemented in native look for each platform. For example, to ask the user a yes/no question:
tk_messageBox -type yesno \
-message "Ok to proceed?" \
To open an existing file:
set file [tk_getOpenFile]
The standard dialogs are described in Chapter 36 starting at page 515.