How do i make input text have to have at least 3 letters and if they have any less show a erro message. As2
===

ok so am trying to make a game and right now i can make it so if they enter nothing it shows a error but the problem with that is you can still just put one letter and i need them to have at least 3 letters in the input text field any less and my error_txt will say ("error you must enter at least 3 letters") please help i cant find this any ware else any help would be greatly appreciated! 

ok my code on my button is:

    on (release) {
	if (texter_txt.length == 0)
	{
		error_txt.text = ("please enter a name.");

	}
	else
	{
	
		_root.gotoAndStop(2);
	}
}