"darine", The Java Ranch has thousands of visitors every week, many with surprisingly similar names. To avoid confusion we have a naming convention, described at http://www.javaranch.com/name.jsp . We require names to have at least two words, separated by a space, and strongly recommend that you use your full real name. Please choose a new name which meets the requirements. Thanks.
Just like JAVA, JSP is case sentitive. According to the code, it should have two different instance of "beans.StringBean". One is "mybean", another one is "myBean". Maybe even you import the package, jsp still require you to use the full class name includes the whole package for the "class=?".