Basic PHP that returns a string based on input

I want to be able to make a call to a php script on my website that performs a search and returns a response based on what was supplied. If the search item doesn't exist, it should be added to the database. The url will be encoded. For example (in my app): var uri = "[login to view URL]"+encodeURIComponent(planName); If the planName exists, the script should return the values in the table row relating to that plan seperated by a newline (\n): R=Result (will be "FAIL" or "SUCCESS") P=Peak Quota (amount shown in MB) O=Off-Peak Quota (amount shown in MB) U=Uploads Included (will be "TRUE" or "FALSE") V=VoIP URL (will be the URL for VoIP usage) If planName doesn't exist, it should be added and flagged for admin action. Result should be FAIL and email sent to admin Admins should have a login that views the database contents and enables them to adjust values in each row and save.