title: Check if <form> text element is null
body: <p>I wanted to do an error check in Javascript which would pop up if a form-text element is empty.</p>
  
  <pre><code>var itemPrice = parseFloat(document.getElementById("tPrice").value);
  
  if(itemPrice &lt; 0 || itemPrice == null)
  {
    alert("Please enter a valid price");
    return false;
  }   
  </code></pre>
  
  <p>I have tried <code>itemPrice == "null"</code>and <code>itemPrice === "null"</code>.</p>
  
  <p>Any insight would be great, thank you!</p>