InfoPath Dev

Hi, total noob here need help !!

I have a list in sharepoint called consumables.
Description            Price
a4 paper               10
a5 paper               12
paper clips            25

What I am trying to do is have a repeating table in an InfoPath Form where the user can select the description and the relevant price is displayed.

The price is incorrect always e.g 10 when I select a different Product in each repeating table.

Guess I am not understanding something here.

Here is the xpath for the price field which is a lookup on the sharepoint list.
xdXDocument:GetDOM("Consumables")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:cPrice[../d:Description = xdXDocument:get-DOM()/my:myFields/my:group7/my:group8/my:field16] 

Any help would be most appreciated. 

Is group8 your repeating group? And field16 contains the description? And this is a default value on the price field which is in the same repeating group as field16

If so, you want this:
xdXDocument:GetDOM("Consumables")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:cPrice[../d:Description = current()/../my:field16] 

If that isn't right, please feel free to attach your form template to the Options tab in a reply so I can take a quick peek at it and get you the right XPath.

 (PS - if this form is not in production, please go back through your main data source and give groups and fields meaningful names! It makes your life sooooooo much easier!)

 appreciate the help !

 Aplogise for the bad naming ! I have just renamed the repeating table.

xdXDocument:GetDOM("Consumables")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:cPrice[../d:Description = xdXDocument:get-DOM()/my:myFields/my:group9/my:RepeatingTable/my:Item] 

 Thank you very much Hilary, that has worked a treat !!