Fix Customer List Website - coding issue

Have a simple 2 page customer list php application. It connects to MSSQL Database. It is working 90% but needs one major logic fix. When searching for customers from the MSSQL database, the customer search is working and customers can be added to build a customer list, but every time a new search is done, the entire list is erased. Need to be fixed .Other small fixes is the layout of the customer list needs to be smaller and some error when exporting to CSV.

Have all the PHP pages and live MSSQL data connection for testing.

Fix 1: Fix the customer list to allow multiple searches
Fix 2: Make the customer list smaller in spacing
Fix 3: Fix errors in CSV export
Needs to be done in 3 days - absolute deadline