classi??

[noemi::.::clown]

sentite delle classi non capisco niente...e quindi della pillola su upload+resize... non ho capito niente, qualcuno sa dirmi come si include una classe e cosa è questo errore?

Fatal error: Cannot instantiate non-existent class: imageresized in d:\documenti\uni\2sem-3anno\basi di dati\heck\album_foto\pages\upload_1.php on line 107


Fatal error: Call to undefined function: imagecreatefromjpeg() in d:\documenti\uni\2sem-3anno\basi di dati\heck\album_foto\pages\upload_1.php(143) : eval()'d code on line 1


e poi... perchè al posto di eseguire il codice della classe me lo printa? non c'è nessun comando che gli dice di farlo.

ecco il contenuto della classe:

class ImageResized {

    /**
    * vars used to manage operations
    */
    var $type, $img, $size, $dest, $name;

    /**
    * public constructor
    *    ImageResized( $imageToCopyResized, $newSize [, $destinationFolderToCreateResizedImage ] );
    */
    function ImageResized( $img, $size, $dest = '' ) {
        $this->img = &$img;
        if( file_exists( $this->img ) == true ) {
            $this->type = &UcFirst( strToLower( $this->__file_extension( $this->img ) ) );
            $this->name = &substr( $this->img, 0, -( strLen( $this->type ) + 1 ) );
            if( $this->type == 'Jpg' ) {
                $this->type = 'Jpeg';
            }
            $this->size = &intVal( $size );
            $this->dest = &str_replace( '//', '/', $dest.'/' );
            $this->__createImage();
        }
    }

    /**
    * private method, called from constructor
    *     Check size to mantain aspect ratio, verify image type and show or create new resized image
    * @param    none    no params need
    * @return    none    headers with new image / create new image
    */
    function __createImage() {
            $imgSize = getimagesize( $this->img );
        $imgX = $imgSize[0];
        $imgY = $imgSize[1];
        $newY = floor( ( $imgSize[1] * $this->size ) / $imgSize[0] );
        eval( "\$img_original = imageCreateFrom{$this->type}( \"{$this->img}\" );" );
        $img_final = imageCreateTrueColor( $this->size, $newY );
        imageCopyResampled( $img_final, $img_original, 0, 0, 0, 0, $this->size, $newY, $imgX, $imgY );
        if( $this->dest != '/' && is_Dir( $this->dest ) ) {
            eval( "image{$this->type}( \$img_final, '{$this->dest}{$this->name}.".strToLower( $this->type )."', 100 );" );
        }
        else {
            header( "Content-type: image/{$this->type}" );
            eval( "image{$this->type}( \$img_final );" );
        }
        imageDestroy( $img_original );
        imageDestroy( $img_final );
    }

    /**
    * private method, called from constructor