Excel 2007 : Calculating Fee depending on info in another cell

Hi All

I am new on here and really need your help. I have a spreadsheet and in column P i have engineers names and in L i have the fee. I was to calculate the amount each engineering is turning over each year. So for example all of Johns clients I want the fees added together in a totals box at the bottom of my sheet. I have tried an IF statement but I think I am inputting it wrong.

Can anyone please help me?

Thanks
Gemma

Perhaps use the SUMIF function?