//This example returns the row index.
// Press Ctrl key to merge
$(document).keydown(function (e) {
     if (e.keyCode === 17) {
         spread.options.allowUserDragMerge = true;
     }
});
$(document).keyup(function (e) {
     if (e.keyCode === 17) {
         spread.options.allowUserDragMerge = false;
     }
});
activeSheet.bind(GC.Spread.Sheets.Events.DragMerging, function (e, data) {
     var mergeRange = data.mergeRange;
     alert(mergeRange.row);
});
activeSheet.bind(GC.Spread.Sheets.Events.DragMerged, function (e, data) {
     var mergeRange = data.mergeRange;
     alert(mergeRange.row);
});