I have had similar issues with charts and reports for my Access programs. This issue revolves around the way Access queries handle the parameter inputs. Everytime the data is sorted, queried, or refreshed the parameters need to be input again. The best work-around I found was to use input boxes on a form that hold the values needed to run the report or chart and all the queries behind them.
I used a combo-box with the indexed values behind it to solve the issues that arise from user input to display the chart.
1) Redundant entries aren't user-friendly
2) What if they enter the data differently the second or third time?
3) What if they enter a value that is the wrong data type or isn't a valid entry?
By giving the user a list to choose from, the value is in place and can be passed to the criteria for the query. It has to be a valid entry if selected from the list. This eliminates the user having to enter the data more than once. On the form I created with the combo-boxes for user selection, I placed a button that opens the report or chart and passes the value to the criteria input based on the combobox value.
I hope this points you towards a solution for your issues.
Bryan Meek
bmeek@pacbell.net
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