Calculating Commissions

Hi,

I am not so good at more than basic formulas. I have built a spreadsheet where I want to calculate a salesperson's commission based on how their sales were to their goal. However, while their commission percentage is based on how their sales were to goal, their payout at that percentage is a percentage of cash received from their clients that month. (I didn't design the system)

As an example, there is a total sales goal field (M8), a total actual sales for the month field (M12) and a field where cash received is keyed (M16)

If the person's sales are less than goal (M8) they get paid 6% of M16.If they are 100% - 109% of M8, they get paid 8% of M16 and if they are 110% or higher of goal, they get paid 10% of M16.

So, I need Excel to look at the total goal, look at the total sales and calculate a payout of the cash received number at the proper percentage based on how well they did to goal.

Any help would be greatly appreciated.

Thanks!