Closing Windows

[Delbert Martin <dmartin kionix com>]

Ok for a program i am designing i have a login button. i would like to make this login window disappear on a successful login but if unsucessful i would like the window to stay.
Is there anyway way to do this?

i am using a function to create the window and the window is a Global Widget.
how would i tell that window to close? only that window. 

thanks
--Delbert Martin IV