关于useBean

再网页中插入<jsp:useBean id="compare" scope="page" class="compare_scope"/>运行后，tomcat报错为：
The server encountered an internal error () that prevented it from fulfilling this request.
不知为什么啊？compare_scope.class(源文件如下：)public class compare_scope
{
private String scopeType;
public void setscopeType(String scopeType)
{
this.scopeType=scopeType;
}
public String getscopeType()
{
return scopeType;
}
}