calling registerstartupscript from outside class

[o0JoeCool0o]

I am trying to call Page.RegisterStartupScript from a method in a user
control.
I am getting a null reference error whenever I try to use
Page.RegisterStartupScript.
I trying to set the focus of a button on my user control...
however this gets called from a method inside the user control
not the main page. so how do I reference the Page class without getting
this null reference error?