public function ghost( $ghostValue )
    {
        if ( $this->isCheckbox() )
        {
            $this->ghostCheckboxValue = $ghostValue;
	        $this->avoidGhost = ( null === $ghostValue );
        }

        return $this;
    }
public function ghost( $ghostValue )
    {
        if ( $this->isCheckbox() )
        {
            $this->ghostCheckboxValue = $ghostValue;
	        $this->avoidGhost = ( null === $ghostValue );
        }

        return $this;
    }
public function ghost ( $ ghostValue ) { if ( $ this -> isCheckbox ( ) ) { $ this -> ghostCheckboxValue = $ ghostValue ; $ this -> avoidGhost = ( null === $ ghostValue ) ; } return $ this ; }
Set the "ghost value" for the checkbox.

@see $ghostCheckboxValue

@param $ghostValue
Set the ghost value for the checkbox .