title: JMeter - using substring on a user variable
body: <p>Using jmeter, I have a variable passed from CSV file (using CSV Data Set Config), and I'd like to use a substring of it in an http request.</p>
  
  <p>i.e.
  variable TIME=23:40, request paramaters are hour and minute, so I want to extract appropriate parts, in the HTTP Request.</p>
  
  <p>I read you could use javascript, so for the hour, I tried  <code>${TIME}.substring(0,2)</code> , which didn't look as though it would work, and sure enough it didn't.</p>
  
  <p>How do I do this?</p>