var customFloatingObject = new GcSpread.Sheets.CustomFloatingObject("f1", 10, 10, 60, 64);
var btn = document.createElement('button');
btn.style.width = "60px";
btn.style.height = "30px";
btn.innerText = "button";
customFloatingObject.Content(btn);
activeSheet.addFloatingObject(customFloatingObject);
// Use IE to see the console log text
$("#spreadContainer").data("spread").getActiveSheet().bind(GcSpread.Sheets.Events.FloatingObjectSelectionChanged, function (e, info) {
console.log("sheet name: " + info.sheetName);
});