How can I close a browser window without getting a standard browser confirm box? This is ****ting me up the wall...

This is the code I am using... the 2nd window opens fine, but the one I am in keeps asking for a second opinion. Goddamn it!!!

window.close();
window.open("login.asp", "LoginWindow", "menubar=no, directories=no, location=no, resizable=no, toolbar=no");