How to create a scolling combo box?

[OmniX]

I would like to create a scrolling combo box.

By which I mean.

<select>
<option>1</option>
<option>2</option>
<option>3</option>
<option>4</option>
<option>5</option>
<option>6</option>
</select>

Should appear as just 1 option (so maybe size="1') and then once clicked it expands with the options with a scrollbar which only 3 options shown and you scroll to see the rest of the options.

Hopefully you understand what I mean?

Thanks, Regards X

Note: Not sure if this requires just html but I heard requires javascript, Thanks.