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>