$fieldset->addField('title', 'text', array(
          'label'     => Mage::helper('form')->__('Title3'),
          'class'     => 'required-entry',
          'required'  => true,
          'name'      => 'title',
          'onclick' => "alert('on click');",
          'onchange' => "alert('on change');",
          'style'   => "border:10px",
          'value'  => 'hello !!',
          'disabled' => false,
          'readonly' => true,
          'after_element_html' => '<small>Comments</small>',
          'tabindex' => 1
        ));

http://www.excellencemagentoblog.com/magento-admin-form-field

Magento Admin Form

form, forms, magento

PHP