USB/serial get thermistor temp to html/php

I have been searching High and Low from yesterday and today from 06:00 until now 10:12 and can not seem to find any relevant information for my situation.

I have an arduino Uno R3 and a computer with Firefox and I have a web hosting XAMPP.

I have successfully loaded all needed sketches and php pages to switch three LED's on or off via my web browser. So my comms are working great.

Only problem now...
How do I read analog value from my arduino into my php web page. Also my analog input comes from a 10K thermistor so i want to convert it to Celsius?

I do not have an ethernet shield at the moment so i am doing this via the USB cable (serial port).

Whenever you have separate programs your best bet is to use files to store variable values. Sometimes it's unavoidable, but you may not have another choice if you cannot make one single app.