PostbackUrl по сравнению с NavigateUrl

const verificationFunction = (value) => {
  alert("here we are runnning the verification over " + value)
}
var x = function x() {
  var element = document.getElementsByName("verify")[0];
  if (element.value.length >= 4) {
    verificationFunction(element.value)
  }
}

<input type="text" name="verify" maxlength="4" onkeyup="x()" />