Add a new field to your form:

<div>
    <label for="text3">Disabled: </label>
    <input type="text" name="text3" id="text3" value="Ha ha can't get me">    			
</div>

Save and try and you should have a new text input field under the user name (but above the password).  It should work the same as any other text field (try it) because that is all it is for now.

Add a new disabled attribute so that it looks like this:

<div>
    <label for="text3">Disabled: </label>
    <input type="text" disabled name="text3" id="text3" value="Ha ha can't get me">    			
</div>

Save and try again.  You should see the field but not be able to get the cursor or any data into it.

This might not seem useful but you can disable fields at first and then use JavaScript to enable them once necessary things have been done by the user.  You can also disable the submit button the same way.  Feel free to try that but undo the change afterwards as you will need this form to work later.  No data is sent to the server when you submit a disabled field.

Readonly

Change the disabled attribute to readonly.  Save and try.  You should now be able to click and the cursor will go into the field but you cannot type anything.  This could be used for holding data you want the user to see but not change (a product ID from when they clicked on an "order me" button maybe).  The data is sent when you submit the form.