Excel If & Then

Hello,
I wanted to know that, in Excel 2007, what is the formulae if Cell B12 has a drop down list of 3 range and if we select a particular range then cell C12 must enter a custom text.

E.G.: Suppose Cell B12 has a drop down list of 3 range(Normal, High, Urgent)
Now if we select Normal in cell B12 then cell C12 must show (To be considered in 15 days) and
If we select High in cell B12 then cell C12 must show (To be considered in 5 days) and
If we select Urgent in cell B12 then cell C12 must show (To be considered in 02 days)

Please suggest soon if this can be done.

Regards