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Which version of ChronoForms are you using?
If you have Joomla! 1.6, 1.7 or 2.5 then you are using ChronoForms v4.
If you have Joomla! 1.5 then you could be using either ChronoForms v3 or v4.
If you have Joomla! 1.0 then you are using a very old version of ChronoForms :-(
You can find the exact version from Site Admin | Extensions | Install/Uninstall | Components in Joomla! 1.5
or Site Admin | Extensions | Extension Manager | Manage in Joomla! 1.6, 1.7, or 2.5.
Please see this FAQ for the main differences between CFv3 and CFv4.