Quantity sum up on a Page.

Hello,

I hv created a page 'Prod Entry Line' with three fields i.e. 'Item Type' which is an option fiels, 'Issued Net Kgs.' & 'Quantity' which are Decimal fields.I also declared few options for 'Item Type' field, i.e. Paper Roll, Scrap Ink & so on.

Now I need to Sum all the quantities of the 'Paper Roll' option of the 'Item Type' field & show this details within the 'Issued Net Kgs. field. I also hv declared the 'Issued Net Kgs.' field as a flowfield in 'Item Journal Line' table.

I can't able to do this.Please Help!

Thank You,