Hi Andy,
You'll want to add a couple of actions to the the 'Actions after add' and 'Actions after edit' (Steps 6 & 7 of the grid wizard). The actions you will want to use are:
Get sum (from the Weight column of the InvoiceLine grid)
Enter value into field on screen (to enter the sum into the weight subtotal field you added).
Hope that helps!
Matt Raiser
Founder,
www.techinthefield.com
matt@techinthefield.com
219-221-9500
~ Method user / partner since 2008
~ Over 15 years field service experience
~ 2013 Method Partner of the Year
~ Degree in Computer Science
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