Logged off successful Pop up disable for URL's

Hi All,

we have set up WEBGUI/SSO ( SPnego)  ie when user clicks on URL it does log in automatically using SSO which works fine but

When user logs off the screen it gives a information pop up saying " Logged off Successfully" which we dont want and it also gives any option to close the pop up but gives only restart application option.

Please can any one let us know how to disable this pop up after login of from the link.

Thanks in advance.