how can I use this function -xmldoc ()

[Anon]

hi everybody ~

I want to use dom, so i install dom-modules

• configure --with-xml -with-dom=/libxml -

and install apache webserver , it's not error

so i use function related with dom -xmldoc()

but, i can't use these function

error message is like that

Fatal error: Call to undefined function: xmldoc()

help~ please , what's the wrong ?