Added opening comments and wrote code block for check if file exists in working directory and downloads the file if not.
Completed script for plot1. It first checks to see if the data frame exits, if not it downloads the file and reads the data of interest into a data frame. It then converts the date and time strings into a single column of class POSIXlt. This check has been put into a function so it can be reused.

After this is done it creates the histogram of global active power