title: Check if text field is empty before executing jQuery
body: <p>This might be a very easy question, but I find it confusing.</p>
  
  <p>How do I run myFunc() if <code>textField_1</code> is not empty?</p>
  
  <p>Excicute <code>.on('click', '#openButton', myFunc)</code> if <code>($('#textField_1').val()!="")</code> ?</p>