<SCRIPT>
function removeit(){
  obj=document.testForm.testSelect;
  lastobj=obj.options[(obj.options.length-1)];
  alert(lastobj.text+'['+lastobj.index+'] 삭제');
  obj.remove(lastobj.index);
  obj.focus();
}
</SCRIPT>

<FORM name=testForm>
<SELECT id=testSelect size=9>
<OPTION>선택 1
<OPTION>선택 2
<OPTION>선택 3
<OPTION>선택 4
<OPTION>선택 5
<OPTION>선택 6
<OPTION>선택 7
<OPTION>선택 8
<OPTION>선택 9
</SELECT>
<INPUT type=button value='선택 항목 삭제'   onClick="removeit()">
</FORM>