Creating new Excel and adding required no. of sheets using .Net variables

I’m facing problem in adding additional sheets to an excel .

while executing the below code I’m able to create new excel sheet,

After creating the excel file I’m not able add additional sheets to that excel.

It is showing error like

prob.png

Please suggest any possible ways of adding sheets.

Thanks in Advance.

Hi,
This should help
saurav-nav.blogspot.in/…/nav-2013-r2-multiple-sheets-in-excel.html

Thanks for your reply,

I have done this already using Excel buffer. But I want it by using .Net variables.