Showing a scrollbar only in Firefox

I'd like to have a scrollbar at the bottom of the div but this CSS works only in Firefox, not Webkit browsers like Safari or Chrome.

div.hoge {
     width: 500px;
     overflow: auto;
 }
 

I googled and found some pages mentioning you should use overflow-x or -webkit-overflow-scrolling but they didn't work either. Need to use some JSs? Any guesses?

---