Prime Numbers

Get all the prime numbers between two points.

HTML

<input type="number" id="primeStart" placeholder="starting number">
<input type="number" id="primeEnd" placeholder="ending number" />
<button onclick="primerize();">get Primes</button>
<output id="result">
  <ul id="primeList"></ul>
</output>

CSS

input:focus,
button:focus {
  outline: none;
  border: 1px solid #1EBE28;
}

input {
  padding: .618em;
  border: 1px solid #ccc;
  border-radius: 2px;
}

button {
  color: white;
  padding: .618em;
  border: 1px solid #1EBE28;
  border-radius: 3px;
  background: rgb(30, 190, 40);
}

button:hover,
button:focus {
  background: rgb(25, 158, 33);
}

li {
  color: #333;
  font-size: 1.2em;
  padding: 0;
  line-height: 1.618
}

JavaScript

function addToList(num) {
  var li = document.createElement('li'),
    list = document.getElementById('primeList');
  li.innerText = num;
  list.appendChild(li);
}

function clearList() {
  var list = document.getElementById('primeList');
  list.innerHTML = '';
}

function primerize() {
  clearList();
  var numArray = [],
    primeArray = [],
    start = document.getElementById('primeStart').value !== null ? document.getElementById('primeStart').value : 0,
    end = document.getElementById('primeEnd').value != null ? document.getElementById('primeEnd').value : 20;
  for (var i = 0; i < end; i++) {
    var divisArray = [];
    numArray.push(i);
    [].forEach.call(numArray, function(num) {
      if (i % num === 0) {
        divisArray.push(num)
      }
    });
    if (i >= start && divisArray.length <= 2) {
      primeArray.push(i);
      addToList(i);
    }
  }
}