You might try FileSaver + FileReader.
BTW, the "expression: BankToString" will get a string, so user only need to save this string.
Working example Capx-Download
Capx also has a DRAG AND DROP option..so Podes Drag and drop plugin needed-LINK
Working in Chrome browser.
Test in browser here-TESTchrisbrobs2013-03-11 14:49:35