Edit HTML/PHP Form and save in Mysql

I have one Invoicing System which has Quotation and Sales Invoice preparation forms. Following work has already done :- 1. Create Quotation - Done (But need to check calculation). 2. Edit Quotation - Not Done 3. Sales Invoice - Quotation will change into Quotation but need to add 4-5 additional fields. Like Invoice date, Driver number, Vehicle Number, Transport Charges etc. Need to save in Mysql Database. 4. Edit Sales Invoice - Not done. We need to make a common screen for add and edit operation. If Quotation number or sales Invoice is available in the parameter then it will update previous data else will create new entry.