This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
The most likely cause of this error is a simple spelling mistake. Is com.ibm.FirstAForm really the name of the class, or did you misspell it in the struts-config.xml file? Did you compile the class? Is the .class file in WEB-INF/classses?