Java J2ee Planet

As part of our project we have to deliver the EARs to the client. Usually we use Ant script to run the build.xml file. But this when we are running build.xml using ant script, we have faced the following error. The RAD / Eclipse console is show the following message stating that ·          “build\build.xml:251: Problem: failed to create task or type projectBuild” ,“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. See the exact error that displayed on RAD/Eclipse console