Comaprison analysis in line chart in Qliksense

[anindya_manna]

Hello Experts,

I am creating a line chart with date in x axis and sales in Y axis.I have to draw a vertical reference line on a particular date in which a campaign have been held in order to compare sales before campaign and after campaign like below.

I need help on following points.

1. Is it possible to draw a vertical reference line in line chart in Qliksense?
2. Please give me some idea to visualize this data before sales and after sales of campaign.I need to show this comparison.