Computer Repair Work Order Database2

I require a automated numeric database form computer repair work order. This form will be used when a customer requires PC repair. The salesperson will fill out all the information on the screen and then print two copies. One signed and kept and the other copy goes to the customer. Please note the work order number must increase automatically and the date must also be automatically inserted from system date and time But these fields must also be editable. The fields must include an area for serial number up to 80 characters and requires all fields. I also require a field to allow price/hour and for it to automatically calculate taxes for an estimate. This will not be used to issue an invoice just a quote. I require to be able to edit fields easily encase tax amount change or field description change.