Access custom sub on user control from another form

I'm trying to access a custom sub written within a user control. For instance:

A button is clicked on a form, and I want the WebCoreShutdown() to fire when a button is clicked within another form. Is this even possible? Is it also possible to access attributes from an element within the user control (such as Awesomium), and alter the attributes at runtime? Because no matter what with either of these things I'm asking, it always of course says it's not declared. I'm just trying to figure out how to correctly declare the custom sub from another form. Thank you, and I apologize if this is a bit of an amateurish question. I'm still learning the language after all.