how to make application fast when one process is going on and user click another button or link

Hi
on my page i have grid control when user select a row and click the button on the page then popup is open with
the help of Model PopUpExtender(ModalPopupExtender). Following is the code

string path = "ReferenceReport.aspx?GenDate=" + textboxRateGenDate.Text.TrimEnd() +"&HotelID=" + this.LabelHotelID.Text.TrimEnd() +"&rowindex=" + rowIndex;

AjaxControlToolkit.ModalPopupExtender ModalPopupExtender1 = new AjaxControlToolkit.ModalPopupExtender();
ModalPopupExtender1.ID = "ModalPopupExtender1";
ModalPopupExtender1.PopupDragHandleControlID = "DaragPanel";
ModalPopupExtender1.PopupControlID = "pnlrefrenceReport";
ModalPopupExtender1.TargetControlID = "Button1";
ModalPopupExtender1.BackgroundCssClass = "modelBackGroundforRateReport";
...