function input_filterAmt (str, dec, bNeg)
{ // auto-correct input - force numeric data based on params.
	var cDec = '.'; // decimal point symbol
	var bDec = false; var val = "";
	var strf = ""; var neg = ""; var i = 0;

	if (str == "") return parseFloat ("0").toFixed (dec);

	if (bNeg && str.charAt (i) == '-') { neg = '-'; i++; }

	for (i; i < str.length; i++)
	{
		val = str.charAt (i);
		if (val == cDec)
		{
			if (!bDec) { strf += val; bDec = true; }
		}
		else if (val >= '0' && val <= '9')
			strf += val;
	}
	strf = (strf == "" ? 0 : neg + strf);
	return parseFloat (strf).toFixed (dec);
}