I need to know exactly what to say to him? helpp?

I'm FALLING head over heels for my BEST FRIEND! He's important to me, & if I lost him I wouldn't know what to do he means a lot & well I REALLY like him & I wanna tell him to find out if he likea me too; I just don't want to lose him incase I tell him & he doesn't. But I get a vibe that he does. He told my friend he liked me & she told him I liked him too but now were still just friends & well he's always askin me to go out with him to the mall with him & his friends & I wanna tell him but what exactly should I say? D: