In my database i have 5 catagories of product and 7 performance parameters for each product. My table contains fields TestDt, ProdCat, P1, P2 ... P7.
I have made a form for datewise chart for each product for each parameter. The form contains two combo boxes one listing product catagories other listing performance parameters. Through a macro I make the chart to change for perticular product catagory when I change my selection in combo box. But the same I am not able to do for performance parameters since those are different colums.
Can somebody help.

Your Performance Parameters need to be ONE COLUMN and NOT seven.

You need to re-design your db and have a seperate linked table with a field simply called 'Performance' and ProdCat or better still ProductID.

You then need to create a 'one to many' relationship between Categories Table and Performance Table.

So, something like this

Table:Categories
Fields: [CatID], [CatDescription]
(Primary Key is [CatID])

Table:Performance
Fields:[CatID],[PerformanceID],[Performance]
Primary Key is [PerformanceID](Auto) or you could have both [CatID] AND [Performance] as a composite Primary key IF these two together will always be unique.

Hope this all makes sense!