If you want to use a js variable in a php script you MUST pass it within a HTTP request. There are basically two ways: Submitting or reloading the page.
Explanation:
In programming, just like in algebra, we use variables in expressions (total = price1 + price2). From the example above, you can calculate the total to be 11. JavaScript variables are containers for storing data values. All JavaScript variables must be identified with unique names. These unique names are called identifiers.
