IF function/vlookup ??

[Shermaine2010]

Hi all,

I have to set formula to calculate allowance entitlement.Amount based on the event's month salary as baseline. Allowance entitlement is 1 month salary or maximum 2,000.
Each person have own date of salary increment and also date of event.

Example :
Old salary before July 2011 = 1,500
new salary onwards July 2011 = 2,500
Meant that event allowance for month June is 1,500 and after July 2011 is 2,000.

Please refer the attachment for more detail.

Thank you

regards.