Session problem?

[mallikarjun dontamsetti]

Hi, I am trying to display the records of database by user entered in search boxes like first name,last name,and it has to guide to grid page after that when i click the view/edit options the it has to show the data after modifying the the page has to return to grid page.but it is showing some error
Here my code

       HttpSession ls=request.getSession(false);
       if(ls==null){
           response.sendRedirect("Login.html");
       }
       else{
           String uname=ls.getAttribute("UserName").toString();
           String name=uname.concat("-Malli");
           StudentDB studentDB=new StudentDB();
           String OPERATION;
           String DISCRIPTION;
           LoginDB ldb=new LoginDB();
            //Getting the parameter values from the search form
            String searchOption1=request.getParameter("searchOption1");
            String searchOption2=request.getParameter("searchOption2");
            String searchOption3=request.getParameter("searchOption3");
            String str1=request.getParameter("fname");
            String str2=request.getParameter("lname");
            String str3=request.getParameter("sal1");
            String Action=request.getParameter("Action");
            String s1=request.getParameter("STD_SNO");
            HttpSession session =request.getSession(true);
           //Setting values to option bean
           Option op=new Option();
           
           op.setSearchOption1(searchOption1);
           op.setSearchOption2(searchOption2);
           op.setSearchOption3(searchOption3);
           op.setFname(str1);
           op.setLname(str2);
           op.setSal1(str3);
           int eid;
           
           
          // /*-----------------------------------------------------
           String searchQuery;
           
         //  ------------------------------------------------------------*/
           
           if(Action.equals("Search")){
               response.sendRedirect("complexsearch.jsp");
           }
           
           
           else if(Action.equals("showAll")){
               System.out.println("--------------------");
               
               if(session.isNew()){
               searchQuery=studentDB.searchQuery(op);
                  session.setAttribute("searchQuery",searchQuery);
                  System.out.println("----------new----------");
               }else{
                  searchQuery=session.getAttribute("searchQuery").toString();
                  System.out.println("----------noooo----------");
               }
               
               List<Student> showList=studentDB.showAll(searchQuery);
               session.setAttribute("student",showList);
               System.out.println("upto here");
               DISCRIPTION="User searched the database";
               OPERATION="Search";
               ldb.LoginConform(name,OPERATION,DISCRIPTION);
               
               response.sendRedirect("studentinformation.jsp");
               
           }else if (Action.equals("view") || Action.equals("edit")) {
                eid = Integer.parseInt(s1);//Getting the sn number
                //Setting the value of depatment object to display in jsp
                
                List<Student> viewList = studentDB.viewStudent(eid);
                session.setAttribute("viewList", viewList);
                //condition to guid to perticular page
                if (Action.equals("view")) {
                String destination = "viewstudent.jsp";
                response.sendRedirect(destination);
                } else {
                response.sendRedirect("editstudent.jsp");
                }
            }

Exception

Error 500--Internal Server Error
java.lang.NullPointerException
at COM.GARNET.EMPLOYEE.StudentController.doPost(StudentController.java:82)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3498)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(Unknown Source)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2180)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2086)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1406)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)

[mallikarjun dontamsetti]

Sorry my problem is solved i was checking session perhaps i have to check the the value null