为什么数据库中有帐号和密码，登陆的时候还提示我帐号不存在

今天下午SSH整合的人事系统，终于被我弄完了，在TOMCAT上发布。可是在管理员登陆的时候却出现了这个毛病


                                http://localhost:8080
                                                      您的帐号不存在    
下面是这个管理员Action的代码：
package com.wy.action;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.actions.DispatchAction;

import com.wy.dao.ObjectDao;
import com.wy.form.ManagerForm;

public class ManagerAction extends DispatchAction {
    private ObjectDao objectDao;

    public ObjectDao getObjectDao() {
        return objectDao;
    }

    public void setObjectDao(ObjectDao objectDao) {
        this.objectDao = objectDao;
    }

    // 用户登录操作
    public ActionForward checkManager(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response) {
        ManagerForm managerForm = (ManagerForm) form;
        HttpSession session = request.getSession();
        ManagerForm managerform = (ManagerForm) objectDao
                .getObjectForm("from ManagerForm where account='"
                        + managerForm.getAccount() + "'");
        if (managerform == null) {
            request.setAttribute("errorNews", "您输入的账号不存在");
        } else if (!managerform.getPassword().equals(managerForm.getPassword())) {
            request.setAttribute("errorNews", "您输入的密码不正确");
        } else {
            session.setAttribute("managerform", managerform);
        }
        return mapping.findForward("checkManager");
    }

    // 用户修改操作
    public ActionForward updateManager(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response) {
        ManagerForm managerForm = (ManagerForm) form;
        String result = "用户修改失败！！！";
        if (objectDao.updateObjectForm(managerForm))
            result = "用户修改成功！！！";
        request.setAttribute("result", result);
        return mapping.findForward("operationManager");
    }

    // 用户察看操作
    public ActionForward queryManager(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response) {
        List list = objectDao
                .getObjectList("from ManagerForm where managerLevel!=1");
        request.setAttribute("list", list);
        return mapping.findForward("queryManager");
    }

    // 用户保存操作
    public ActionForward insertManager(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response) {
        ManagerForm managerForm = (ManagerForm) form;
        ManagerForm managerform = (ManagerForm) objectDao
                .getObjectForm("from ManagerForm where account='"
                        + managerForm.getAccount() + "'");
        if (managerform == null) {
            objectDao.insertObjectForm(managerForm);
            return queryManager(mapping, form, request, response);
        } else {
            request.setAttribute("result", "您输入的账号重复，请重新输入");
            return mapping.findForward("errorManager");
        }
    }

    // 用户删除操作
    public ActionForward deleteManager(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response) {        
        ManagerForm managerform = (ManagerForm) objectDao.getObjectForm("from ManagerForm where id='"
                        + request.getParameter("id") + "'");        
        objectDao.deleteObjectForm(managerform);
        return queryManager(mapping, form, request, response);        
    }

}
我不知道是不是登陆操作代码有问题，请高手为小弟指导下。