var aTags = document.getElementsByTagName("a");
var sText = "All";
var aTags;

for (var i = 0; i < aTags.length; i++) {
  if (aTags[i].textContent == sText) {
    var v = aTags[i].getAttribute("onclick");
    v = v.replace(/\D/g,'');
    break;
  }
}

if(document.getElementById("seeneps").value < 4 && v <= 16) {
  errorVal = 'You must see at least 4 episodes before writing a review';
  }
 if(document.getElementById("seeneps").value < 6 && v >= 17) {
  errorVal = 'You must see at least 6 episodes before writing a review';
  }
 if(document.getElementById("seeneps").value < 10 && v >= 48) {
  errorVal = 'You must see at least 10 episodes before writing a review';
  }