Occuring error when i am running GWT in netbeans-Collection of common programming errors

undeploy-clean:
C:\Users\ashfaque\Documents\NetBeansProjects\webapp\nbproject\build-impl.xml:1405: Problem: failed to create task or type nbundeploy Cause: The name is undefined. Action: Check the spelling. Action: Check that any custom tasks/types have been declared. Action: Check that any / declarations have taken place.

BUILD FAILED (total time: 0 seconds)

Originally posted 2013-11-09 23:06:33.