Your profile shows 2003, but you uploaded a .xslx file, so i will assume you have 2007 or later (please update your profile)

If you mean that you want to be alerted is Manual Hrs+DCC Hrs exceed 16, then you can do this with conditional formatting...

1. highlight the range you want to apply the conditional formatting to
2. on the home tabe, styles, select CF
3. select new rule, select use formula
4. enter =($J2+$G2)>16