JS function to enable and disable inputs as the previous was filled

validateControl.js

function validateRelationshipForm(inputs) {
  for (i = 0; i < (inputs.length - 2); i+=2) {
    if (inputs[i].value.length > 0) {
      inputs[i + 1].disabled = false;
      if (inputs[i + 1].type == "button") {
        inputs[i + 1].classList = ("btn btn-success");
      }
    } else {
      inputs[i + 1].disabled = true;
      if (inputs[i + 1].type == "button") {
        inputs[i + 1].classList = ("btn btn-secondary");
      }
    }
  }
}