alignment problem

Hi there,

I have a small question due to the alignment.

In the gallery section where all the pictures from the album are displaied, how can I set a value to separate the left pictures from the margin. So, how can how can I remove the top-left alignment and enter a left value to separate the pictures from the left margin?

Thanks in advance

http://ww.wp.xz.cn/plugins/gallery-plugin/