function checkPassword(field1, field2, length) {
	var invalid = " "; // Invalid character is a space
	var minLength = 6; // Minimum length
	var pw1 = field1.value;
	var pw2 = field2.value;

	// no password change
	if (pw1 == '' && pw2 == '') {
		return true;
	}
	// check for a value in both fields.
	if (pw1 == '' || pw2 == '') {
		alert('Please enter your password twice.');
		return false;
	}

	// check for minimum length
	if (length && pw1.length < minLength) {
		alert('Your password must be at least ' + minLength + ' characters long. Try again.');
		return false;
	}

	if (pw1 != pw2) {
		alert ("Passwords does not match. Please re-enter your password.");
		return false;
	} 
	
	return true;
}