Unable to Run web application in Netbeans IDE6.5.1...?

[Shrikant Deshpande]

I am using NetBeans IDE 6.5.1 , created a Web application.

When I Run it , the following error occurs at run time.

Please help me.

Could not load definitions from resource org/netbeans/modules/java/j2seproject/copylibstask/antlib.xml. It could not be found.
init:
deps-module-jar:
deps-ear-jar:
deps-jar:
library-inclusion-in-archive:
D:\MYPROJECTS\LoginPage\nbproject\build-impl.xml:508: Problem: failed to create task or type copyfiles
Cause: The name is undefined.
Action: Check the spelling.
Action: Check that any custom tasks/types have been declared.
Action: Check that any <presetdef>/<macrodef> declarations have taken place.
BUILD FAILED (total time: 0 seconds)