Most of the functions take attributes that specify or modify their behavior. Attributes to Smarty functions are much like HTML attributes. Static values don't have to be enclosed in quotes, but it is recommended for literal strings. Variables may also be used, and should not be in quotes. Some attributes require boolean values (true or false). These can be specified as either unquoted true, on, and yes, or false, off, and no. {html_options values=$vals selected=$selected output=$output} ]]>