How to (use | compile) gettext with clearsilver ?

Hello,
I use clearsilver with fastcgi/lighttpd. I have problem in this file :

hello.html : 
<h1><?cs var:_("hello world !") ?></h1>

After Refresh my page, error : 

An error occured:
Traceback (innermost last):
  File "cgi.c", line 1361, in cgi_display()
  File "csparse.c", line 454, in cs_parse_file()
  File "csparse.c", line 710, in cs_parse_string()
  File "csparse.c", line 1636, in var_parse()
  File "csparse.c", line 1460, in parse_expr()
  File "csparse.c", line 1414, in parse_expr2()
ParseError: [/var/dev/www/fcgiroot/tpl/page/hello.html:6] Unknown function _ called

GetText is enabled (Gettext message translation...OK)   !!, i don't understand...!


help me please

thanks