Joomla Custom Server Side Va

Model.php

/**
	 * Validate Data
	 */
	function validate($form, $data,$group=null){
		$status=true;
		if(!$this->EmailValidate($data['email'])){
			$status=false;
		}
		if($status){
			return $data;
		}else{
			return false;
		}
	}

	/**
	 * Validate Invidation Email
	 */
	function EmailValidate($email){

		$db=JFactory::getDBO();
		$db->setQuery('SELECT * FROM #__users WHERE `email`='.$db->quote($email));
		$db->query();
		$num_rows = $db->getNumRows();
		if($num_rows>0){
			$this->setError("$email this email is already registered with us");
			return false;
		}else{
			return true;
		}
	}