Error in instantiate java class through Tasklistener

[chetan1]

I am new in activiti i am trying to execute java class which implements Task Listener through Activity Diagram when I click on start process from the activiti explorer it gives  exception as " could not instantiate the java class" .how to resolve it.

[martin_grofcik]

Hi.

Did you place your class file into classpath?

Regards
Martin