Tracking Time off as it is earned and used

[bqheng]

Hi,

I have an excel file that tracks leave records for our staff, including unrecorded time offs. In the masterlist tab, time offs are tracked for individual staff and a column for total time off gained. What i hope to have is when a staff enters the time off he is taking into the month tabs, the balance column in the masterlist will reflect how much time off that staff has after minus the time off gained. Can someone help me with that?

Attached is the file