Dashed Gridline

Hi all please see the attached excel chart. I got it from here:
http://www.databison.com/index.php/b...roup-in-chart/

Link to excel sheet is at bottom of that page Ill post here as well: http://www.databison.com/wp-content/...p-in-chart.xls

I'm trying to get the same gridline look. When I download his excel file and check the line style on his gridline it says "No Line" and I'm so confused, how did he get this look on his gridlines?

Also: if you look at his chart in step 5 and compare it to step 6. In step 5 chart, if you select the bars then select one bar and change the fill, then there is like 2px overflow of the bar on the x-axis. But if you change the fill in his step 6 chart there is no overflow. I can't figure this one out either, please help.

Thanks!