title: Why won't my code run my IF-ELSE statement correctly?
body: <pre><code>function checkPIN(pin) {
    if (isNaN(pin)) {
      console.log(pin, ' is not a number');
    } else {
      console.log(pin, ' is a number');
    }  
  }
  
  checkPIN(12sf34);
  </code></pre>
  
  <p>Still quite new to this and cannot for the life of me work out why i can't get a simple check of whether something is a number or not to work?</p>
  
  <p>At the moment i'm getting two errors:</p>
  
  <p>On the above: </p>
  
  <blockquote>
    <p>Uncaught SyntaxError: missing ) after argument list</p>
  </blockquote>
  
  <p>And on a similar piece of code, it accepts that something is a number and runs my con-log. But when it's NOT a number, it gives an 'undefined' to the letters/not-a-number value.</p>
  
  <p>Can i not use isNaN in a function? 
  Is there a reason why i need an extra bracket/parenthesis somewhere? I cannot for the life of me see a requirement for an extra one.</p>