The structure of the depts document is as follows:
<depts> <dept> <emps> – repeats under <depts> <emp> – one for each <dept> <emp_id> – one for each <emp> <emp_name> – one for each <emp> <phones> – one for each <emp> <phone> – repeats under <phones> <phone_no> – one for each <phone> <projects> – one for each <dept> <project> – repeats for each under <projects> <project_id> – one for each <project> <dept_id> – one for each <project>
