I am having trouble complining this servlet, i always get this error, i am using JBuilder5 and Crystal Reports10, the error is :

"report.java": Error #: 302 : cannot access class com.crystaldecisions.reports.reportengineinterface .JPEReportSourceFactory; class file has wrong version 47.0 at line 7, column 59

this is the code i am using :

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import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import com.crystaldecisions.report.web.viewer.*;
import com.crystaldecisions.sdk.occa.report.data.*;
import com.crystaldecisions.reports.reportengineinterface .JPEReportSourceFactory;
import com.crystaldecisions.sdk.occa.report.reportsource. *;
public class report extends HttpServlet {
private static final String CONTENT_TYPE = "text/html";
/**Initialize global variables*/
public void init() throws ServletException {

}
/**Process the HTTP Get request*/
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter();
String report = "c:/Tomcat4/webapps/edcnewest/WEB-INF/classes/Companies.rpt";
IReportSourceFactory2 rptSrcFactory = new JPEReportSourceFactory();
IReportSource reportSource = (IReportSource) rptSrcFactory.createReportSource(report, request.getLocale());
try{
CrystalReportViewer viewer = new CrystalReportViewer();
viewer.setReportSource(reportSource);
viewer.setReportSource("/Companies.rpt");
viewer.processHttpRequest(request,response,getServ letConfig().getServletContext(),out);
viewer.dispose();
}
catch(Exception e){
}
}
/**Clean up resources*/
public void destroy() {
}
}
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any suggestion or help would be greatly appriciated, thank you in advance