read 2 tables - update a coloumn in one table

I want to write a stored procedure that reads 2 tables and sets ‘Status’ on Table 1 to ‘C’ if request is complete .
Please advise – I am new to Sql programming . …..

I have 2 tables

Requests & Bookings (Table 1 and Table 2)
For each request for a room there are many booking records .

Read each record in Table 1 and corresponding records in Table 2.
.
If ToDateTime = system date or ToDateTime > systemdate on Table2 then Status needs to be changed to ‘C’ on Table 1 .

Table 1

RequestID 005
RequestDate 1/1/2011
Name Smith
Email smth@abc.hotmail.com
Tel 01552366662
RoomNo 12
Location T1
Status NC etc etc
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Table 2

BookingID 001
RequestID 005
RequestDate 1/1/2011
FromDateTime 1/1/2011 09.00
ToDateTime 1/1/2011 10.00
BookedBy Smith

BookingID 002
RequestID 005
RequestDate 11/1/2011
FromDateTime 12/1/2011 09.00
ToDateTime 12/1/2011 13.00
BookedBy Smith

BookingID 003
RequestID 005
RequestDate 1/1/2011
FromDateTime 13/1/2011 09.00
ToDateTime 13/1/2011 10.00
BookedBy Smith

BookingID 004
RequestID 005
RequestDate 14/1/2011
FromDateTime 15/1/2011 09.00
ToDateTime 15/1/2011 10.00
BookedBy Smith

If ToDateTime = system date or ToDateTime > systemdate then status needs to be changed to ‘C’ on Table 1 .