error:You cannot use an internal table as a work area

REPORT  Z_EMPL_PERSONAL.

TABLES : zemployees , zpersonal_detail.

TYPES:  BEGIN OF ty_details1,
         employee TYPE zemployees-employee,
         title TYPE zemployees-title,
         forename TYPE zemployees-forename,
         surname TYPE zemployees-surname,
         gender TYPE zemployees-gender,
         salary TYPE zemployees-salary,
         END OF ty_details1,

         BEGIN OF ty_details2,
         employee TYPE zemployees-employee,
         address2 TYPE zpersonal_detail-address2,
         address3 TYPE zpersonal_detail-address3,
         email TYPE zpersonal_detail-email,
         contact TYPE zpersonal_detail-contact,
         END OF ty_details2,

         BEGIN OF ty_details3,
         employee TYPE zemployees-employee,
         title TYPE zemployees-title,
         forename TYPE zemployees-forename,
         surname TYPE zemployees-surname,
         gender TYPE zemployees-gender,
         salary TYPE zemployees-salary,
         address2 TYPE zpersonal_detail-address2,
         address3 TYPE zpersonal_detail-address3,
         email TYPE zpersonal_detail-email,
         contact TYPE zpersonal_detail-contact,
         END OF ty_details3.


         DATA: it_details1 TYPE TABLE OF ty_details1,
               wa_details1 TYPE ty_details1,
               it_details2 TYPE TABLE OF ty_details2,
               wa_details2 TYPE ty_details2,
               it_details3 TYPE TABLE OF ty_details3,
               wa_details3 TYPE ty_details3.


         SELECT-OPTIONS s_Emplye for zemployees-employee.

IF sy-subrc = 0.


            SELECT employee title forename surname gender salary
                 from zemployees
                    into corresponding fields of it_details1
                       where zemployees-employee in s_Emplye.


            select employee address2 address3 email contact
                from zpersonal_detail
                   into corresponding fields of it_details2
                   FOR ALL ENTRIES IN it_details1
                     WHERE employee = zemployees-employee.
              ENDIF.
             
             
            LOOP AT it_details1 INTO wa_details1.
            READ TABLE it_details2 into wa_details2 with KEY employee = wa_details1-employee.  
             IF sy-subrc = 0.
               MOVE wa_details2-employee to  wa_details3-employee .
               MOVE wa_details2-address2 to wa_details3-address2.
               MOVE wa_details2-address3 to wa_details3-address3.
               MOVE wa_details2-email to wa_details3-email.
               MOVE wa_details2-contact to wa_details3-contact.
             ENDIF.  
                    
               move wa_details1-title to wa_details3-title.
               move wa_details1-forename to wa_details3-forename.
               move wa_details1-surname to wa_details3-surname.
               move wa_details1-gender to wa_details3-gender.
               move wa_details1-salary to wa_details3-salary.
        
          append wa_details3 to it_details3.
         
            ENDLOOP.
           
      LOOP AT it_details3 to wa_details3.
         write: / wa_details2-employee,
                  wa_details3-title,
                  wa_details3-forename,
                  wa_details3-surname,
                  wa_details3-gender,
                  wa_details3-salary,
                  wa_details3-address2,
                  wa_details3-address3,
                  wa_details3-email,
                  wa_details3-contact.

      ENDLOOP.

this program gives errors on select statement  ( " You cannot use an internal table as a work area"  )