Close portal main window without confirmation message

Hi All,

Is it possible to close the Portal Main Window (main page) without a confirmation popup window.

I am launching an iView (can be excel sheet/html page etc) using Quick Link which is attached to a role.

When this iView opens, I want to close the portal main page.

I am using the below code to close the main window.

window.top.close()

But it is prompting a confirmation popup window "Do you want to close this window". I don't want this popup message.

I have tried with below code also, but it is neither prompting nor closing the window.

window.opener=null;
window.close();

window.opener=self;
window.close();

Can anyone tell me how to acheive the above requirement.

Thanks

Chinna.