Is the E1000-CADGrantTotal on the same page as the CustormerInfo.Qty and E1000-CADUnitTotal fields? Or is E1000-CADGrantTotal a grand total of all the pages?
There is a shortcut for inserting references to a field in the script editor. With focus in the script editor at the point you want the reference, hold down the CTRL key and click on an object on the design view, and the object’s relative SOM expression will be inserted into your script.
Might be easier to post a link to your form if you can.