If you click on the Forgot your password? Click here! link, you can see that this page too needs customization:

To customize the preceding page, duplicate the file you created for the login page, login.phtml, and name it forgotpassword.phtml in the same bookstore folder under app/design/adminhtml/default/bookstore/template.

What we need to do is only change the title using the following code:

<div class="form-title">

  <h1><?php echo Mage::helper('adminhtml')->__('Forgot your user name or password?'); ?>
  </h1>

  <h2><?php echo Mage::helper('adminhtml')->__('Insert your email to restore the password'); ?>
  </h2>

</div>

Then, change the content of the form, inserting only the e-mail input as follows:

<div class="input-container">

  <input type="text" id="email" name="email" value=" "class="required-entry input-text forgot-password validate-email" placeholder="<?php echo Mage::helper(...