title: How to exclude read only fields using :input in jquery?
body: <p>thus far i've only been using some basic jquery selectors and functions.
  but i'm looking at this <a href="http://www.learningjquery.com/2007/08/clearing-form-data" rel="noreferrer">clear form function</a> and i can't figure out how to add it so i can remove hidden inputs and readonly input from getting cleared.</p>
  
  <p>can anybody help?
  thanks.</p>
  
  <pre><code>function clearForm(form) {
    // iterate over all of the inputs for the form
    // element that was passed in
    $(':input', form).each(function() {
   var type = this.type;
   var tag = this.tagName.toLowerCase(); // normalize case
   // it's ok to reset the value attr of text inputs,
   // password inputs, and textareas
   if (type == 'text' || type == 'password' || tag == 'textarea')
     this.value = "";
   // checkboxes and radios need to have their checked state cleared
   // but should *not* have their 'value' changed
   else if (type == 'checkbox' || type == 'radio')
     this.checked = false;
   // select elements need to have their 'selectedIndex' property set to -1
   // (this works for both single and multiple select elements)
   else if (tag == 'select')
     this.selectedIndex = -1;
    });
  };
  </code></pre>