请教一下在php5smarty3的环境中怎么使用popup_init

<{popup_init src="/web/smarty/js/overlib.js"}>
为什么我的模板文件一只报错Uncaught --> Smarty Compiler: Syntax error in template ".\templates\test.html" on line 31 "<{popup_init src="/web/smarty/js/overlib.js"}>" unknown tag "popup_init" <-- thrown in E:\FileWorkSpace\myweb\smarty\libs\sysplugins\smarty_internal_templatecompilerbase.php on line 31