Error 1009 at SetIntervalTimer/onTimer()

Please to any professional know .. I have this codes

var timeout:Number = setTimeout(DAndM(Cover1, Text1, Box1), 7000);

function DAndM(Cover:MovieClip, Text:TLFTextField, Box:MovieClip)
{
     Cover.x = 0;     Text.x = 0;     Box. x = 0;
}

And for know Cover1 and Box1 is a movieclip in resource and Text1 is a TLFTextField

So my error show is

TypeError: Error #1009: Cannot access a property or method of a null object reference.

     at SetIntervalTimer/onTimer()

     at flash.utils::Timer/_timerDispatch()

     at flash utils::Timer/tick()

Thanks for helping me