Cannot creat excel file in application folder of client system in build

In my application i am dynamically creating an excel to show its preview.When preview button is clicked a copy of excel file is dynamically created in bin\debug folder of my application it is opened to show preview. It works fine in the application , but wen the application is run using its build excel file not creating in application folder. I gave complete premission for application folder bt still problem exist.

Plz.. help me..