Jquery Slider - getting value into php

Jquery Slider - getting value into php

hi all. I'm a php guy who uses jquery ui, but not very good with javascript. What i have is a working jquery ui slider, that works no problem. I have it on a database update form. I have successfully made it so that on loading the form, it sets the value of the slider to that of a particular database field. all that works. 

BUT...

when the user presses the "save" button on my form, the php does all the mySQL saving of the data using a standard UPDATE statement. What i am unsure how to do though, is how to get the value of the jquery slider into a php variable so that i can use the value to update the database. so in pseudo code :

$phpVariable = (some function that gets) jquerySlider.value

i'm sure it's a piece of cake for many of you but i can't find the answer searching. help!