extjs 4 grails spring login

[Anand]

hi i want to authenticate user from extjs login page using spring security core 1.1.3 plugin. i am referring to this tutorial

http://loianegroner.com/2010/02/integrating-spring-security-with-extjs-login-page/

but when i click on login button it says 

Failed to load source for: http://localhost:8080/Wave/j_spring_security_check 

in firebug. maybe i dont know where to put those file or where to integrate in grails. here is what i did in context of tutorial..

created login.js in web-app/js/login.js

created applicationContext-security.xml in web-app/web-inf/applicationContext-security.xml

created MyAuthenticationProcessingFilter in src/java/MyAuthenticationProcessingFilter