SQL & PL/SQL :: Matching Query

i have two table menu_user_d and emp_master , the requirement is i need to match names from both these tables like i want want to match menu_user_d.user_desc to emp_master.emp_name to get the emp_id and update the correct emp_id into menu_user_d.user_emp_id , i have prepared a test case and wrote one query but could'nt succeed in getting all the matching names, is there a way i can do this correct matching and then update it automatically.

SQL> create table menu_user_d (user_id varchar2(12),user_desc varchar2(30),user_emp_id varchar2(12));

Table created.

SQL> insert all
2 into menu_user_d(user_id,user_desc,user_emp_id) values ('ARIF','Mohammed Arif',null)
3 into menu_user_d(user_id,user_desc,user_emp_id) values ('wajahat','Wajahat',null)
4 into menu_user_d(user_id,user_desc,user_emp_id) values ('Imad','Imd',null)
5 select * from dual;

3 rows created.

SQL> commit;

Commit complete.

SQL> create table emp_master (emp_id varchar2(12),emp_name varchar2(30));

Table created.

SQL> insert all
2 into emp_master(emp_id,emp_name) values ('7014','Md.Arif')
3 into emp_master(emp_id,emp_name) values ('6777','Wajahat')
4 into emp_master(emp_id,emp_name) values ('1008','Imad El Kane')
5 select * from dual;

3 rows created.

SQL> commit;

Commit complete.

SQL> SELECT USER_ID,USER_DESC,USER_emp_id,EMP_id,EMP_NAME
2 FROM MENU_USER_d,EMP_master
3 WHERE UPPER(USER_DESC) LIKE UPPER(EMP_NAME) ;

USER_ID USER_DESC USER_EMP_ID EMP_ID EMP_NAME
------------ ------------------------------ ------------ ------------ ------------------------------
wajahat Wajahat 6777 Wajahat