$('#InstrumentListGrid').delegate('.ui-iggrid-activerow', 'dblclick', function (e)
This is just using the jQuery delegate function to attach a function to the dblclick event of the element. '.ui-iggrid-activerow' is just the selector, which I got from looking at the class that was attached to the element when it became the active row. See http://api.jquery.com/delegate/ for the jQuery delegate spec.
var dataview = $('#InstrumentListGrid').data('igGrid').dataSource.dataView();
Again, using the jQuery selector to get the grid – $('#InstrumentListGrid') – I then get the current dataView (the data rows being currently displayed on the page) from the grid datasource, so that I can then access the correct row in the following lines of code.
HTH,
Dane.