My phone is frozen on the "find my iphone alert"

I lost my phone and after using the noise option for find my iphone, the alert will not go away. It is frozen on my screen. The screen is not working besides on the "okay" of the alert, but the alert will not go away. I cannot restart/power down the phone cause I am unable to slide the power off switch. I cannot get into my phone because it requires me to enter my password and the screen isn't letting me select anything on the screen. It will not register on itunes when I plugged it into my computer without me unlocking the phone. Please help.