GoogleSoapSearchApi problem with noclassfound error in the Eclipse RCP program

Hi,all

I started my first Eclipse RCP program with this:
http://www.l3s.de/~olmedilla/students/docs/eclipseRCP-2.pdf

to use the googleSoapSearchApi(can be found in
http://code.google.com/apis/soapsearch/ ),
and it works ok in a standard program,
but when I used it in the Eclipse RCP program like the book above told
me,it will throw the error
"noClassDefFound:GoogleSearchResult"
as known,I had import the googleapi.jar,
and it can found "GoogleSearch" which is in the same
package"GoogleSearchResult",
I'm confused ,and is the RCP import is different?
btw,I use the Eclipse3.2.0 the sample code is :
public class SearchView extends ViewPart{
         ......
         public void createPartControl(Composite parent) {
                GoogleSearch search = new GoogleSearch();
        search.setKey(SearchView.LICENSE_KEY);
        search.setQueryString("search");
        try{
            GoogleSearchResult result = search.doSearch();
            System.err.println("Result:"+result);
        }catch(GoogleSearchFault gsf){
            gsf.printStackTrace();
        }
         }
}

best regards,
Richard