I am attempting to plot a time history plot of how a specific variable reacts over a given amount of time.  However, I also need to plot a vertical line that indicates an "event marker."  This marker is when the pilot performed some type change that may have affected the results. 
I read FAQ (section 4.17 - How do I plot a vertical line), however, was unable to continue with the code.  I have a lot of questions in regards to using this feature.  Below is a script file that I am using to perform my plot.  Where and how would I add the code to plot a vertical line at a specific x location or over a range of x locations?  I will need to be able to do both of these.  Any help would be appreciated.
Chirag Patel