I'm sure I've done this before but I cant find any online resources on this topic to remind me...

After the user has changed the text of textboxA and moved the mouse off that particular control, I would like my method to be executed. What bool expression determines whether the user's mouse has left the control?

Code:
if (!textboxA.Focused && textboxA.Text != String.Empty) // textboxA.Focused isnt working!
{
        ExecuteMethod();
}