Provide the ability to add a horizontal line to a chart in Excel

[Avi]

At times an event happends for which a horizontal line is a good visual
indicative of the expected change in a timeline chart.

 

[Andy Pope]

Hi,

Try this sites for some examples of adding lines to charts

http://tushar-mehta.com/excel/charts/straight_lines/index.html
http://peltiertech.com/Excel/Charts/AddLine.html
http://www.andypope.info/charts/averageline.htm

Cheers
Andy