Netscape 4.x Browsers do not apply width values to SELECT tags via CSS. The proprietary WIDTH attribute must be used in the SELECT tag. Netscape 4.x and Microsoft 4.x browsers respond appropriately to the inline STYLE attribute shown below:
<SELECT
NAME=test
SIZE=1
STYLE="width: 250px;"
WIDTH=250>
<OPTION VALUE="1">This is 1</OPTION>
<OPTION VALUE="2">This is two</OPTION>
<OPTION VALUE="3">This is 3</OPTION>
</SELECT>