CSS - use a horizontal scrollbar only

i need to use an horizontal scollbar only if the content of the div is longer than the width value.

so i write :

.viewgallerylist{width:920px; float:left; padding-top:20px; height:120px; border-bottom:1px #000000 solid; overflow-x: scroll;}

the problem is that the scrollbar are 2, 1 horizontal and 1 vertical. How to remove the vertical one? cheers