C#, how to detect new application being open?

I am using a library ( *.dll ) tha开发者_运维技巧t keeps popping out a window ( which appears as an application in the task manager ) , like "are you sure?..." Yes/No when a certain function is executed.

Is there some way to automatically detect this window/form/application being opened and to close it?

Thanks!

`button.performclick` - 

http://msdn.microsoft.com/en-us/library/system.windows.forms.button.performclick.aspx