choose file name
file save dialog
Puts up a standard Save File dialog (default button "Save"), with title "Choose File Name" and default prompt "Specify new file name and location." The user can also create a new folder. If the user specifies an existing file, goes through the usual "Replace?" rigmarole. You can set the initial folder, the initial filename, and the prompt. Returns a file URL (which appears as a file specifier). Does not actually save anything.