function validateCNPJ(cnpj) {
    cnpj = cnpj.replace(/[^\d]+/g,'');
    if (cnpj.length != 14) return false;
    // Remove known invalid CNPJs
    if (cnpj === "00000000000000" ||
        cnpj === "11111111111111" ||
        cnpj === "22222222222222" ||
        cnpj === "33333333333333" ||
        cnpj === "44444444444444" ||
        cnpj === "55555555555555" ||
        cnpj === "66666666666666" ||
        cnpj === "77777777777777" ||
        cnpj === "88888888888888" ||
        cnpj === "99999999999999") return false;
    // Validate Blocks
    const blocksDivision = cnpj.length - 2
    const headBlock = cnpj.substring(0,blocksDivision);
    const tailBlock = cnpj.substring(blocksDivision);
    let sum = 0;
    let pos = blocksDivision - 7;
    for (i = blocksDivision; i >= 1; i--) {
      sum += headBlock.charAt(blocksDivision - i) * pos--;
      if (pos < 2) pos = 9;
    }
    let validationCheck = sum % 11 < 2 ? 0 : 11 - sum % 11;
    if (validationCheck != tailBlock.charAt(0)) return false;
    blocksDivision = blocksDivision + 1;
    headBlock = cnpj.substring(0,blocksDivision);
    sum = 0;
    pos = blocksDivision - 7;
    for (i = blocksDivision; i >= 1; i--) {
      sum += headBlock.charAt(blocksDivision - i) * pos--;
      if (pos < 2) pos = 9;
    }
    validationCheck = sum % 11 < 2 ? 0 : 11 - sum % 11;
    if (validationCheck != tailBlock.charAt(1)) return false;
    return true;
}