<?php
class Forms_LpaManageEmailForm extends Zend_Form
{
    protected $_actionUrl;    
    protected $_entry_id;
    protected $_flag;


    public function __construct($actionUrl, $options=null, $entry_id, $flag)
    {
	    $this->addPrefixPath('ZFBlog_Form_Decorator', 'ZFBlog/Form/Decorator/', 'decorator');
	    
	    parent::__construct($options);
	    $this->setActionUrl($actionUrl);
	    $this->setEntryId($entry_id);
	    $this->setFlag($flag);
	    $this->init();	    
    }    
    
    public function setActionUrl($actionUrl) {
        
    	$this->_actionUrl = $actionUrl;
    	return $this;
    }    
    
    public function setEntryId($entry_id){        
    	$this->_entry_id = $entry_id;    	
    	return $this;
    }   
    
    public function getEntryId(){
        return $this->_entry_id['entry_id'];
    }
    
    public function setFlag($flag) {
    	$this->_flag = $flag;
    }
    
    public function getFlag() {
    	return $this->_flag;
    }    
    
    
    public function init()
    {       
         
        $this->setAction($this->_actionUrl)
             ->setMethod('post')
             ->setAttribs(array('id' => 'descriptionform', 'onSubmit' => 'multipleSelectOnSubmit()'));        
        
        $this->clearDecorators();
        

	...		
        
        $this->addElement('hidden', 'id', array(            
            'validators' => array(
                'Digits'
            ),
            'required' => true,
            'value' => $this->_entry_id['entry_id'],
        ));

        ...

        $this->addElement($submit);
        

       ...       
    }
    
    
    private function _addMultiOptionsForMultiSelect()
    {
    		...	
    }
    
    public function render(Zend_View_Interface $view = null)
    {
    	$this->_addMultiOptionsForMultiSelect();
    
    	return parent::render($view);
    }
    
    public function isValid($data)
    {
    	$this->_addMultiOptionsForMultiSelect();
    
    	return parent::isValid($data);
    }
    
}

<?php
class Default_Form_CartReport extends Forms_LpaManageEmailForm
{
    protected $_orderId;    

    public function __construct($actionUrl, $options=null, $entry_id, $flag=null, $orderId)
    {            	    	
    	$this->setOrderId($orderId);
    	parent::__construct($actionUrl, $options=null, $entry_id, $flag);
    }
    
    public function setOrderId($orderId){
    
    	$this->_orderId = $orderId;
    	return $this;
    }

    public function setValue($value)
    {
    	$strippedValue = stripslashes($value);
    	return parent::setValue($strippedValue);
    }
    
    public function init(){          
        parent::init();
        $this->id->setValue('100'); // experimental method. doesn't work... debugger shows 
         //["_value":protected] => string(3) "100" ,  but in HTML output it's empty
        
       /* $this->addElement('hidden', 'id', array(
        		'validators' => array(
        				'Digits'
        		),
        		'required' => true,
        		'value' => '100',
        ));*/ creating the element with the same name doesn't make any sense
          
        Zend_Debug::dump($this->getElements());
                
    }
    
    private function _addMultiOptionsForMultiSelect()
    {
       ...   	       		    
    			    	
    }
    
    public function render(Zend_View_Interface $view = null)
    {
    	$this->_addMultiOptionsForMultiSelect();
    
    	return Zend_Form::render($view);
    }
    
    public function isValid($data)
    {
    	$this->_addMultiOptionsForMultiSelect();
    
    	return Zend_Form::isValid($data);
    }  
          
}