Why does Firebug say toFixed() is not a function?

Question

I am using jQuery 1.7.2 and jQuery UI 1.9.1. I am using the code below within a slider. (http://jqueryui.com/slider/)

I have a function that should test two values a

Answer 1

Low is a string.

.toFixed() only works with a number.

A simple way to overcome such problem is to use type coercion:

Low = (Low*1).toFixed(..);

The multiplication by 1 forces to code to convert the string to number and doesn't change the value. JSFiddle code here.