Data transformation

I have to transform data from a 1 week survey to usable data.

Based on the 'personID', 'day of the week', 'Tottime' and 'Activity' I have to calculate for each person how many time he spends on the different types of activities per day. The example in the attachment (reply)will make things more clear. Everything has got to be done by functions because of the size of the real survey.

I hope anyone can help me with this problem!

Thx in advance!