allocate resource date to be two days and response time changes

Dear All,
I am confusing about the allocation date field in resource allocation of service
mgt. The problem is how to allocate resource to the two days of service. Work hour
is 8 hours a day. if I set 10 hours for qty to allocate, the resource availability
becoming -2 hours. I just want that allocation date can be adjusted to be
allocation date start and finish according to service order starting and finish date.
Is it possible to do it ? I will ask the programmer to do that here if yes.
If I set directly starting date today and the expected finishing date the day
after tomorrow, the actual response time is filled automatically meanwhile the service
order status still pending. I thought it must be filled after repair status changed
to in process, mustn’t it?
tku beforehand for your answer.