Loading Text Variables Inside Movieclip

programming flash
1

Hello kirupa guru’s i really need you help.
I want load text variables to the movieclip inside.
heres the script.

on (release) {
	_root.txtBox.text = "Messages"; \\outside movieclip WORKS FINE
	_root.contentMc.txtBox.text = "Messages"; \\inside movieclip NOT LOADING
}

Thanks in advance…