Get Options will generate the options belong to a custom field. Perfect for advanced search forms!
Usage:
{exp:get_options field_name="field_name"}
<option value="{option_value}">{option_name}</option>
{/exp:get_options}
field_name="" - The short name of the custom field to pull values from.
Optional parameters:
sort="alpha" - Sort the values alphabetically. If this is not set, they will be displayed in the order they appear in the database.