function rvcFieldMinLength (formName, fieldName, minLength)
{
	var fieldLen;
	eval ("fieldLen = document." + formName + "." + fieldName + ".value.length;");
	if (fieldLen < minLength)
	{
		alert ("O campo " + fieldName + " deve ter no mínimo " + minLength + " dígitos.");
		return false;
	}
	return true;	
}