captcha not working after hosting..but in localhost works perfectly

In my contact page captcha not working after hosting…but in localhost works perfectly…

after hosting the captcha and the corresponding error message is missing…what i do…?

anyone can help me…please…?

my siteContrioller


public function actions()

{

                  return array(


		// captcha action renders the CAPTCHA image displayed on the contact page


		'captcha'=>array(


			'class'=>'CCaptchaAction',


			'backColor'=>0xFFFFFF,





		),

public function actionContact()

{


	$model=new ContactForm;


	if(isset($_POST['ContactForm']))


	{


		$model->attributes=$_POST['ContactForm'];


		if($model->validate())


		{


			$model->createContact();


			$name='=?UTF-8?B?'.base64_encode($model->name).'?=';


			$message='=?UTF-8?B?'.base64_encode($model->message).'?=';


			$headers="From: $name <{$model->email}>\r\n".


				"Reply-To: {$model->email}\r\n".


				"MIME-Version: 1.0\r\n".


				"Content-Type: text/plain; charset=UTF-8";





			mail(Yii::app()->params['adminEmail'],$message,$model->body,$headers);


			Yii::app()->user->setFlash('contact','Thank you for contacting us. We will respond to you as soon as possible...');


			$this->refresh();





		}


	}


	


	$this->render('contact',array('model'=>$model));


}

public function accessRules()

{	


    return array('allow', 'actions' => array('captcha'), 'users' => array('*'));


}

}

my ContactForm.php


public function rules()

{


	return array(


		// name, email, message are required


		array('name, email, message', 'required'),


		// email has to be a valid email address


		array('email', 'email'),


		// verifyCode needs to be entered correctly


		array('verifyCode', 'captcha', 'allowEmpty'=>!CCaptcha::checkRequirements()),


	);


}

public function attributeLabels()

{


	return array(


		'verifyCode'=>'Verification Code',


	);


}

contact.php


<?php if(CCaptcha::checkRequirements()): ?>

&lt;div class=&quot;form-group&quot;&gt;


    &lt;?php echo &#036;form-&gt;labelEx(&#036;model,'verifyCode'); ?&gt;


    &lt;div&gt;


    &lt;?php &#036;this-&gt;widget('CCaptcha'); ?&gt;


    &lt;?php echo &#036;form-&gt;textField(&#036;model,'verifyCode',array('class'=&gt;'captcha-control')); ?&gt;


    &lt;/div&gt;


    &lt;?php echo &#036;form-&gt;error(&#036;model,'verifyCode'); ?&gt;


&lt;/div&gt;


&lt;?php endif; ?&gt;

:( :( :( :( :( :(

Try like this -

http://www.yiiframework.com/forum/index.php/topic/30583-a-nother-captcha-no-image/page__p__151836#entry151836

thanx dear for reply…

i installed the "gd" extension.