|In Joomla! 1.5, form fields were parameters. For that version, you may want to use the corresponding Languages parameter type.|
The languages form field type provides a drop down list of the installed languages for the Front-end or Back-end. If the field has a saved value this is selected when the page is first loaded. If not, the default value (if any) is selected. The value saved is the language tag. For example, for English (United Kingdom) this will be 'en-GB'.
The first option on the list is always '- Select Language -' (which is a translatable string) and is given the value 0.
Example XML parameter definition:
<field name="mylanguage" type="language" client="site" default="en-GB" label="Select a language" description="" />