Quick PHP DB Frontend (1 table) and Email Reminder Function

hello, this is a really quick and easy task which most PHP programmers have already done and which probably only needs some code reuse and brushing up. the task is to create a simple webform to add entries to a table, and to mark entries (invoices) as paid in a second form. furthermore, to write a small script to select invoices according to date_paid and date_entry and send out emails with specific text. details below. ## Deliverables We have a database with two tables: customers: | id | int(11) | NO | PRI | NULL | auto_increment | | date_entry | date | NO | | NULL | | | company | varchar(128) | NO | | NULL | | | contact | varchar(128) | NO | | NULL | | | email | varchar(128) | NO | | NULL | | invoices: | id | int(11) | NO | PRI | NULL | auto_increment | | date_entry | date | NO | | NULL | | | date_paid | date | NO | | NULL | | | id_customer | int(11) | NO | | NULL | | | invoice_number | varchar(64) | NO | | NULL | | | invoice_currency | varchar(4) | NO | | NULL | | | invoice_vat | float | NO | | NULL | | | invoice_amount_net | float | NO | | NULL | | | invoice_amount_gross | float | NO | | NULL | | we are, atm, using various accounting solutions for over 1,300 customers and need a quick and dirty tool to consolidate various systems before migrating the stuff again to the new ERP/CRM solution. The web frontend should make use of a LAMP environment and be able to administrate the INVOICES table only. 2 functions: to add invoices, an html form/script as follows: id - primary key, auto increment date_entry: now() date_paid: default NULL id_customer: < select > html field with [login to view URL] as value, and [login to view URL] displayed invoice_number: text field invoice_currency: < select > with values "GBP", "EUR", and "USD" invoice_vat: checkbox, if ticket, value is 20.00 invoice_amount_net: float, to be entered invoice_amount_gross: float, net if vat is not ticket, otherwise net * 1.20. to list/mark invoices as paid, a web form/script to: list all invoices where date_paid is null and display their invoice_number, and a textfield "date_paid". simple calendar javascript to put the date paid into the field, then submit. update invoices table set date_paid = ... where id = ... should be clear ;-) the reminder function: a simple php script to be run as cron daily: select all invoices where date_paid is null -> check if date_paid+11 days < today -> if yes, get the customer email and contact from the customer table and create a simple email saying invoice is due in 3 days. we will tweak that script later on. any questions, do ask :) happy bidding!