title: Adding placeholder attribute to input HTML
body: <p>I'm attempting to add a placeholder attribute to multiple input tags with unique classes in a form. The form is generated by a plugin so I can't add the attribute in manually. Unfortunately nothing I have tried has worked. 
  Because each placeholder is different I'm address each one separately... </p>
  
  <p>Here's the HTML</p>
  
  <pre><code>&lt;input class="name-field" type="text" id="yourName_38_1" name="yourName" value=""&gt;
  </code></pre>
  
  <p>The jQuery I'm using</p>
  
  <pre><code>$(".name-field").attr("placeholder", "name");
  </code></pre>
  
  <p>When I look in the console I get the following which is referring to line the jQuery is on.</p>
  
  <pre><code>Uncaught TypeError: $ is not a function
  </code></pre>
  
  <p>My understanding of jQuery is very basic. Please help</p>
  
  <p>Thank you in advance.</p>
  
  <p>Dave</p>