Can not reach final if inside function

Question

Hello I have to validate a number and I have a function for it that was translated from another language to javascript. The first two if conditions work but I can not reach the final if. I tried inserting a correct and an incorrect number and it does not reach the final if.

Can someone tell me why can I not reach the final if ?

function strReverse(str) {
  var splitext = str.split("");
  var revertext = splitext.reverse();
  var reversed = revertext.join("");
  return reversed;
}

function validCUI() {
  var v = document.getElementById("cui").value;

  if (v.length < 2 || v.length > 10) {
    alert("Numarul de caractere ale Codului Unic de Identificare trebuie sa fie intre doua si 10 caractere");
    document.getElementById("cui").value = "";
  }

  if (v.charAt(0) === "0") {
    alert("Primul caracter al unui Cod Unic de Identificare nu poate fi 0(zero)!\n\nCorectati valoarea introdusa...");
    document.getElementById("cui").value = '';
  }
  alert("xxx");
  var key = "753217532";
  key = strReverse(key);

  var cuirev = strReverse("" + v.valueOf());
  var control = cuirev.substring(0, 1);
  cuirev = cuirev.substring(1);

  var length = cuirev.length;
  var suma = 0;
  alert("inainte de for");
  for (var i = 0; i < length; i++) {
    suma += parseInt(cuirev.charAt(i), 10) * parseInt(key.charAt(i), 10);
  }
  alert("dupa for");
  suma *= 10;
  alert("inainte de final");
  if ((((suma % 11) == 10) && (control == "0")) || (((suma % 11) != 10) && ((suma % 11).toString() == control))) {
    alert("CUI corect");
  } else {
    alert("CUI incorect");
    document.getElementById("cui").value = '';
  }
}

<input id="cui" type="text" value="" />
<input type="button" onclick="validCUI()" value="validate" />

Answer 1

Please always check your console for errors first!

function strReverse(v){
        var splitext = str.split("");
        var revertext = splitext.reverse();
        var reversed = revertext.join("");
        return reversed;
}

Here, for example you use str while the argument of the function is v, I suppose you meant v.split('');

Answer 2

Change var splitext = str.split(""); to this var splitext = v.split("");