自动调整为最大长度:
<select style=width:expression((this.offsetwidth>100)？'auto':'100')>
<option >hellohellohellohellohellohellohellohellohellohello</option>
</select>
鼠标点时自动变成最大长度,离开或选中时恢复原长度
<select name=s2 style=width:50px onfocus=this.style.width='auto'onblur=this.style.width='50px' onchange=this.style.width ='50px'>
<option>1111111111111111111111111111</option>
<option>2222222222222222222</option>
</select>
鼠标滑过时自动变成最大长度,离开或选中时恢复原长度
<select name=s2 style=width:50px onmouseover=this.style.width='auto' onblur=this.style.width='50px' onchange=this.style.width='50px'>
<option>1111111111111111111111111111</option>
<option>2222222222222222222</option>
</select>
选择后在页面地其它位置显示选择地项目
<div id=dsp></div>
<select name=select size=1 onchange=dsp.innertext=this.options[this.selectedindex].text>
<option value=1>test</option>
<option value=2 selected>test2</option>
</select>
鼠标滑过时显示当前选择地项目地值
<div id=div1 style=overflow:auto;height:expression(5*15);width:expression(document.all.s1.offsetwidth+18);>
<select name=s1 size=1 style=width:120 onmousemove=showtitle(this);onmouseout=hidetitle(this);>
<option>aaaaaaaaaaaaaaaaaaaaaa1 </option>
<option >bbbbbbbbbbbbbbbbbbbbbbbbb1 </option>
<option>cccccccccccccccccccccccc1 </option>
<option>ddddddddddddddddddddddd1 </option>
<option>eeeeeeeeeeeeeeeeeeeeeee1 </option>
<option>fffffffffffffffffffffffffff1 </option>
</select>
</div>
<script>
// 定义popup
var op=window.createpopup();
op.document.body.style.background=beige;
//popup 是否已显示
var opshow=0;
function showtitle(obj){
var h=event.offsety;
var fontsize=(obj.style.fontsize==？(obj.currentstyle.fontsize==？9:obj.currentstyle.fontsize):obj.style.fontsize);
fontsize=parseint(fontsize)*1.6;
var l=parseint(h/fontsize);
op.document.body.innertext=obj.options[l].text;
len=obj.options[l].text.length*8;
op.show(event.offsetx+20,event.offsety+fontsize+5,len,fontsize,document.body);
opshow=1;
}
function hidetitle(obj){
if(opshow==1)op.hide();
}
</script>
