Can't update/delete record & % problem

[lau Apple]

(a) I had create a query with make relation to a table & a query, but I can't update/delete in my query or form.
1. My source table with fields - receipt no, job no(common field), payment date
2. My source query with fields - record no, job no(the job no must be reused after the job is completed, so the job no may be more than one with no filter), customer code, customer name, order date, competed date (filter with "is null")
May anyone can help, Thanks in advance!!

(b) I had create a field in table with format #.00%. When I entry 0.54, it will show 0.00%; when I entry 0.6, it will show 100%. Please help me to adjust this problem, thans in advance!