I've just spent the last couple of hours fighting with CH19 - thankfully with sucess, but decided to post in case anyone else hit the same problem.

Installed Tomcat (5.5.9) and had no major issues (other than CH19 only working through netBeans - cheers diegoborgh).

Installed Struts (1.2.7) which worked, as did adding an error message for the comments field.

Trying to add the mask validation resulted in an

java.lang.NoClassDefFoundError: org/apache/oro/text/perl/Perl5Util error.

In order to get it working I worked out you need to download the ORO Jakarta project and copy the jakarta-oro-2.0.8.jar file in to the struts-base/WEB-INF/lib directory.

you copy jakarta-oro.jar in ant/lib folder into lib folder of application .