Plotting lines in pivot chart
 

Excel2003 SP2
I have 3 worksheets with data in a table to show when we are going to run
out of numbers. There are three scenarios which show different rates of
consumption all crossing the "0" X-axis at different dates. When I change the
chart type from 'bar' to 'line' its fine. When I add the second and third
scenarios, the data point seems to connect to one another giving a zig-zag
affect. How can I get rid of the affect without turning off lines and how can
I show different colors for the three lines?
Thanks in advance for any/all suggestions.
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Thanks for your help, QAFB