Problem with GlassFish, when it deploy , it delete jar file

i used netbeans IDE 6.9.1 for practice EJB and JSF, i don't know why, when i add one Library primefaces it can't deploy Primefaces to server ? I copy jar file of Primefaces to WEB-INF/Li开发者_JS百科b and re-deploy, Glassfish delete jar file on server , and i copy it to folder build/web/WEB-INF/Lib, once again when server deloy EJB App, it remove this jar file, but i test with Web Application it can deploy jar file of Primefaces .

Everybody have any ideas for fix it, or expert have any solution for this problem, please help me !

Thank You!