static public function
fStart(
	vUserName : String,
	vInput : String
) : String
{
	var vScore : int;
//	var vHasLetters : Array = vInput.match(/[a-zA-Z]+/);
	var vHasNumbers : Array = vInput.match(/[0-9]+/g);
	var vHasPunctuation : Array = vInput.match(/[^a-zA-Z0-9]+/);
	var vHasCasing : Array = vInput.match(/[a-z]+.*[A-Z]+|[A-Z]+.*[a-z]+/);
	var vResult : String;

	if (vInput.length == 0) return "It's blank!";
	
	vScore += (vInput.length < 7 ? 0 : 1);
	vScore += (vInput.length >= 12 ? 1 : 0);
	vScore += (vInput.toLowerCase() == vUserName.toLowerCase() ? 0 : 1);
	vScore += (vHasNumbers == null ? 0 : 1);
	vScore += (vHasNumbers != null && vHasNumbers.length <= 4 ? 0 : 1);
	vScore += (vHasPunctuation == null ? 0 : 1);
	vScore += (vHasPunctuation != null && String(vHasPunctuation).length <= 2 ? 0 : 1);
	vScore += (vHasCasing == null ? 0 : 1);
	vScore += (vHasCasing != null && String(vHasCasing).length <= 2 ? 0 : 1);

	switch (vScore)
	{
	case 0:
	case 1:
	case 2:
	case 3:
		vResult = "Weak";
		break;
	case 4:
	case 5:
	case 6:
	case 7:
		vResult = "Medium";
		break;
	case 8:
	case 9:
		vResult = "Strong";
		break;
	}
	return vResult;
}

http://simplistika.com

AS3 Password Strength Meter

ActionScript 3