function getDigit(str, num) {
  i=1;
  if ( num != 1 ) {
  	while (i!=num && str.length!=0) {
		if ( str.charAt(0) == '.' ) {
			i++;
		}
		str = str.substring(1);
  	}
  	if ( i!=num )
  		return -1;
  }
  for (i=0; i<str.length; i++) {
  	if ( str.charAt(i) == '.' ) {
		str = str.substring(0, i);
		break;
	}
  }
  if ( str.length == 0)
  	return -1;
  d = parseInt(str, 10);
  return d;
}

function checkMask(str, num, msg) {
	d = getDigit(str,num);
	if( !(d==0 || d==128 || d==192 || d==224 || d==240 || d==248 || d==252 || d==254 || d==255 )) {
		alert(msg + ' \n' + showText(361));
		return false;
	}
		return true;
}

function validateKey(str) {
   for (var i=0; i<str.length; i++) {
    if ( (str.charAt(i) >= '0' && str.charAt(i) <= '9') ||
    		(str.charAt(i) == '.' ) )
			continue;
	return 0;
  }
  return 1;
}

function maskRule (mask,defname,defVal) {
	if (mask.value == "") {
		alert(showText(362) + ' ' + showText(363));
		if (defVal == 1)
			mask.value = mask.defaultValue;
		mask.focus();
		return false;
	}
	if ( validateKey( mask.value ) == 0 ) {
		alert(showText(364) + ' ' + showText(365));
		if (defVal == 1)
			mask.value = mask.defaultValue;
		mask.focus();
		return false;
	}
	if ( !checkMask(mask.value,1, showText(366))) {
		if (defVal == 1)
			mask.value = mask.defaultValue;
		mask.focus();
		return false;
	}
	if ( !checkMask(mask.value,2, showText(367)) ) {
		if (defVal == 1)
			mask.value = mask.defaultValue;
		mask.focus();
		return false;
	}
	if ( !checkMask(mask.value,3, showText(368)) ) {
		if (defVal == 1)
			mask.value = mask.defaultValue;
		mask.focus();
		return false;
	}
	if ( !checkMask(mask.value,4, showText(369)) ) {
		if (defVal == 1)
			mask.value = mask.defaultValue;
		mask.focus();
		return false;
	}
	return true;
}

function subnetRule(ip, mask, client, str) {
	if (client.value!="" && client.value!="0.0.0.0") {
        if ( !checkSubnet(ip.value, mask.value, client.value)) {
            alert(showText(370) + str + '!\n' + showText(371));
            client.value = client.defaultValue;
			client.focus();
            return false;
        }
    }
	return true;
}
function checkSubnet(ip, mask, client) {
  ip_d = getDigit(ip, 1);
  mask_d = getDigit(mask, 1);
  client_d = getDigit(client, 1);
  if ( (ip_d & mask_d) != (client_d & mask_d ) )
	return false;

  ip_d = getDigit(ip, 2);
  mask_d = getDigit(mask, 2);
  client_d = getDigit(client, 2);
  if ( (ip_d & mask_d) != (client_d & mask_d ) )
	return false;

  ip_d = getDigit(ip, 3);
  mask_d = getDigit(mask, 3);
  client_d = getDigit(client, 3);
  if ( (ip_d & mask_d) != (client_d & mask_d ) )
	return false;

  ip_d = getDigit(ip, 4);
  mask_d = getDigit(mask, 4);
  client_d = getDigit(client, 4);
  if ( (ip_d & mask_d) != (client_d & mask_d ) )
	return false;

  return true;
}