InfoPath Dev

Hi All -

I have a repeating table made from a data connection to a sharepoint list:

/dfs:myFields

    dfs:dataFields

        dfs:DSE_Security_Levels

            @User_Name

            @Centre_or_Department

            @Region

            @Security_Level

            @Status

I am trying to create a field which concatenates the contents of the User_Name field above. I've done this on different forms and lists and it's worked fine. The formula I am using is:

eval(eval(DSE_Security_Levels[@Security_Level = 1],'concat(@User_Name,";")'),"..")

I've used the field picker to put the data connection name and filter in. When I verify the formula, i get:

msxml5.dll
Reference to undeclared namespace prefix: 'dfs'.
Error occurred during a call to property or method 'Eval'.

and the formula changes to:

The full XPath of the formula is:

It looks like the problem is with the User_Name field, but I can't see what it is. I've tried testing it by changing the data connection to another list which has worked before, but I still get this error.

Does anyone have any ideas please?

TIA

Your formula doesn't really make sense the way it is. How's this?

xdMath:Eval(xdMath:Eval(xdXDocument:GetDOM("DSE Security Levels")/dfs:myFields/dfs:dataFields/dfs:DSE_Security_Levels[@Security_Level = 1], 'concat(@User_Name,";")'), "..")