In future, while posting code, please UseCodeTags I have added them this time for you. As you can see they make the code much more easier to read and understand.
This error indicates the said class is not found on the class path.
1) Have you compiled your code? Do you see .class file(s)?
2) How are you running your application. IDE, commandline, anything else? If command line, please copy paste the exact command you are using