I would like to create a formula on excel 2007 as follows:

if (A1)="Overnight tour" I want the following calculation to take place (B1>15,1),(B1>31,2),(B1>47,3),(B1>63,4) and so on .. or maybe the multiplies of 16 to return 1 for each multiply in another form. otherwise (if A1 does not contain "Overnight tour") to return a blank cell ("").

Can anyone please help me with that