If I leave this as a vSelectFile then
Set CreatePrompt_State to False
creates the file silently.

OTOH if I use vSelectSaveFile what we actually need is 'overwriteprompt_state'. The user doesn't BTW find this confusing and I find it more logical.

When using vSelectFile and specifying a file that already exists, 'Set CreatePrompt_State to False' seems to include setting overwriteprompt_state to false too.