Align text left of image in this php script? [closed]

Question

Ok so i am using this code, which allows me to upload photo's to a post and instead of inserting them myself, it calls all the photos attached to the post. Thus for placing all the photos in the post by itself. But what i did was made this page int a gallery where i use a jquery jcarousel where they can click the arrows to go to the next photo.

here is the code

 <?php

if ( 'photos' == get_post_type() ) { //condition to show gallery on post type - photos

if ( $attachments = get_children( array(
    'post_type' => 'attachment',
    'post_mime_type'=>'image',   //return all image attachment only
    'numberposts' => -1,   //get all the attachments
    'post_parent' => $post->ID
)));

foreach ($attachments as $attachment) {
    // you can customize the oputput
    echo '<li><center>';
    echo wp_get_attachment_link( $attachment->ID, 'full' , false, false, '' );
    echo '<span class="img_cap">'.$attachment->post_excerpt.'</span>';
    echo '</center></li>';
}
}

?>

But how do i get the post_excert part of the code which is the caption, to align left of the image, what do i add to the code and where, or is this something i do in css.