selectedIndex以前还真不知道

select name='estimateAchi' id="+id+" onChange='changeEstimatePoint(this)'><option >100-90</option><option >89-80</option><option >79-70</option><option >69-60</option><option >59-0</option></select>

<select name='estimatePoint' id=c"+id+" onChange=''><option value='4'>4</option><option value='3'>3</option><option value='2'>2</option><option value='1'>1</option><option value='0'>0</option></select>

function changeEstimatePoint( o)
{
var id=o.id;
//alert(document.forms[0].estimatePoint[id].id);
//alert(o.selectedIndex);
    document.forms[0].estimatePoint[id][o.selectedIndex].selected=true;
}