Week on Week Sales Comparison using Formula Query

Hi,

We have a sales summary table that has a sales total per week. [Week Ending], FID 6 and [Sales Total], FID7.

We would like to do a week on week sales comparison using a Formula Query (if that is possible)

We have tried various formula queries with this one being the "best" so far.

var text LASTWEEK = "{6.BF.'"& [Week Ending] &"'}";
var text THISWEEK = "{6.AF.'"& [Week Ending] &"'}";

GetRecords($THISWEEK,7)-GetRecords($LASTWEEK,7)

However we are getting the following error;

"The types of the arguments or the number of arguments supplied do not meet the requirements of the function GetRecords.
The function GetRecords can be used with the following arguments:
GetRecords (Text q).
GetRecords (Text q, Text t)."

Any suggestions would be greatly appreciated.

Tim

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Tim Egerton
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