Remove #N/A data from graph

I have a table of 30 rows which look up different values depending on the their column titles. From this table I have created a graph. When I change the column titles sometimes the data does not fill all 30 rows. Therefore I am left with #N/A where the lookups cannot find a value which leaves an area on the graph with no data.

What I want is the graph to expand / contract to show only the valid data. I have a cell that counts the number of valid cells so thought there might be a way of only returning the number of rows that have been counted. Is this possible??!!

Thanks!

I have already used named ranges - can't seem to get it to work arg! Perhaps you can give me some more details? Thanks

Just tried posting the workbook but is too big - can't take anything else out of it though!

could i email it to u?