Can you get one point where you want the vertical line, say at the
bottom of the chart? Then use a vertical error bar for your gridline.
See this web page for details:

http://peltiertech.com/Excel/Charts/...Gridlines.html

- Jon
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Jon Peltier, Microsoft Excel MVP
Peltier Technical Services
Tutorials and Custom Solutions
http://PeltierTech.com/
_______


lsu-i-like wrote:

for some reason, when i try to plot it using x value = 1 and y value =
0,100, instead of a straight line up and down i get a diagonal line. i
am using a xy scatter chart with smooth lines.