css overflow property

I have some images inside a div with a specified height and width display:block;.

What I have a little trouble figuring out, is why, sometimes, whether you tell the overflow y property to appear or not, it still does.

Then again; with the below code, you can get the horizontal scrollbar, but, the content still flows vertically.

overflow-x:none;
overflow-y:hidden;

I would like my images to overflow horizontally only. I don't want the vertical scrollbar..

The above css may create only a horizontal scrollbar, but, still, the images, or text still flows vertically.

What is the best way of solving this?

Thanks in advance.