If the cells are truly empty (i.e., no formula that results in a zero
length string ""), selec the chart then Tools | Options... | Chart tab.
In there set 'Plot empty cells as' to 'Interpolated'

If you do have the "" string, replae it with the NA() function.
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Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article ,
says...
I am using Office 2003 (Excel) to create a line graph representing daily
ranking. However, there are several dates for which values are not available.
Is it possible to have Excel put a flat line in place of the missing values,
connecting only the available data?

Thanks,