更换select下拉菜单背景样式的实现代码

<style> 
.uboxstyle{width:174px;height:39px; float:right;} 
#uboxstyle{width:174px;height:39px; float:right;} 
#uboxstyle .select_box{width:174px;height:39px; float:left;} 
#uboxstyle div.tag_select{display:block;color:#79A2BD;width:174px;height:39px;background:transparent url("images/select01.jpg") no-repeat 0 0;padding:0 10px;line-height:39px;} 
#uboxstyle div.tag_select_hover{display:block;color:#79A2BD;width:174px;height:39px;background:transparent url("images/select01.jpg") no-repeat 0 0;padding:0 10px;line-height:39px; } 
#uboxstyle div.tag_select_open{display:block;color:#79A2BD;width:174px;height:39px;background:transparent url("images/select01.jpg") no-repeat 0 0px;padding:0 10px;line-height:39px;} 
#uboxstyle ul.tag_options{padding:0;margin:0;list-style:none;width:174px;padding:0 0 5px;margin:0;} 
#uboxstyle ul.tag_options li{display:block;width:174px;padding:0 10px;height:30px;text-decoration:none;line-height:30px;color:#79A2BD;text-align:left;} 
#uboxstyle ul.tag_options li.open_hover{color:#000} 
#uboxstyle ul.tag_options li.open_selected{color:#000} 
</style> 
<script language="JavaScript"> 
var selects = document.getElementsByTagName('select'); 
var isIE = (document.all && window.ActiveXObject && !window.opera) ? true : false; 
function $(id) { 
return document.getElementById(id); 
} 
function stopBubbling (ev) { 
ev.stopPropagation(); 
} 
function rSelects() { 
for (i=0;i<selects.length;i++){ 
selects[i].style.display = 'none'; 
select_tag = document.createElement('div'); 
select_tag.id = 'select_' + selects[i].name; 
select_tag.className = 'select_box'; 
selects[i].parentNode.insertBefore(select_tag,selects[i]); 
select_info = document.createElement('div'); 
select_info.id = 'select_info_' + selects[i].name; 
select_info.className='tag_select'; 
select_info.style.cursor='pointer'; 
select_tag.appendChild(select_info); 
select_ul = document.createElement('ul'); 
select_ul.id = 'options_' + selects[i].name; 
select_ul.className = 'tag_options'; 
select_ul.style.position='absolute'; 
select_ul.style.display='none'; 
select_ul.style.zIndex='999'; 
select_tag.appendChild(select_ul); 
rOptions(i,selects[i].name); 
mouseSelects(selects[i].name); 
if (isIE){ 
selects[i].onclick = new Function("clickLabels3('"+selects[i].name+"');window.event.cancelBubble = true;"); 
} 
else if(!isIE){ 
selects[i].onclick = new Function("clickLabels3('"+selects[i].name+"')"); 
selects[i].addEventListener("click", stopBubbling, false); 
} 
} 
} 
function rOptions(i, name) { 
var options = selects[i].getElementsByTagName('option'); 
var options_ul = 'options_' + name; 
for (n=0;n<selects[i].options.length;n++){ 
option_li = document.createElement('li'); 
option_li.style.cursor='pointer'; 
option_li.className='open'; 
$(options_ul).appendChild(option_li); 
option_text = document.createTextNode(selects[i].options[n].text); 
option_li.appendChild(option_text); 
option_selected = selects[i].options[n].selected; 
if(option_selected){ 
option_li.className='open_selected'; 
option_li.id='selected_' + name; 
$('select_info_' + name).appendChild(document.createTextNode(option_li.innerHTML)); 
} 
option_li.onmouseover = function(){ this.className='open_hover';} 
option_li.onmouseout = function(){ 
if(this.id=='selected_' + name){ 
this.className='open_selected'; 
} 
else { 
this.className='open'; 
} 
} 
option_li.onclick = new Function("clickOptions("+i+","+n+",'"+selects[i].name+"')"); 
} 
} 
function mouseSelects(name){ 
var sincn = 'select_info_' + name; 
$(sincn).onmouseover = function(){ if(this.className=='tag_select')this.className='tag_select_hover'; } 
$(sincn).onmouseout = function(){ if(this.className=='tag_select_hover') this.className='tag_select'; } 
if (isIE){ 
$(sincn).onclick = new Function("clickSelects('"+name+"');window.event.cancelBubble = true;"); 
} 
else if(!isIE){ 
$(sincn).onclick = new Function("clickSelects('"+name+"');"); 
$('select_info_' +name).addEventListener("click", stopBubbling, false); 
} 
} 
function clickSelects(name){ 
var sincn = 'select_info_' + name; 
var sinul = 'options_' + name; 
for (i=0;i<selects.length;i++){ 
if(selects[i].name == name){ 
if( $(sincn).className =='tag_select_hover'){ 
$(sincn).className ='tag_select_open'; 
$(sinul).style.display = ''; 
} 
else if( $(sincn).className =='tag_select_open'){ 
$(sincn).className = 'tag_select_hover'; 
$(sinul).style.display = 'none'; 
} 
} 
else{ 
$('select_info_' + selects[i].name).className = 'tag_select'; 
$('options_' + selects[i].name).style.display = 'none'; 
} 
} 
} 
function clickOptions(i, n, name){ 
var li = $('options_' + name).getElementsByTagName('li'); 
$('selected_' + name).className='open'; 
$('selected_' + name).id=''; 
li[n].id='selected_' + name; 
li[n].className='open_hover'; 
$('select_' + name).removeChild($('select_info_' + name)); 
select_info = document.createElement('div'); 
select_info.id = 'select_info_' + name; 
select_info.className='tag_select'; 
select_info.style.cursor='pointer'; 
$('options_' + name).parentNode.insertBefore(select_info,$('options_' + name)); 
mouseSelects(name); 
$('select_info_' + name).appendChild(document.createTextNode(li[n].innerHTML)); 
$( 'options_' + name ).style.display = 'none' ; 
$( 'select_info_' + name ).className = 'tag_select'; 
selects[i].options[n].selected = 'selected'; 
} 
window.onload = function(e) { 
bodyclick = document.getElementsByTagName('body').item(0); 
rSelects(); 
bodyclick.onclick = function(){ 
for (i=0;i<selects.length;i++){ 
$('select_info_' + selects[i].name).className = 'tag_select'; 
$('options_' + selects[i].name).style.display = 'none'; 
} 
} 
} 
</script> 
<div style="width:500px;"> 
<form id="form1" name="form1" method="post" action="?Action=Select" style="padding:0px;"> 
<div style="width:200px; float:left; text-align:left; margin-top:8px;"> 
<div id="uboxstyle"> 
<select name="select1" id="language"> 
<option value="1">Cars...</option> 
</select> 
</div> 
</div> 
<div style="width:200px; float:left;text-align:left;margin-top:8px;"> 
<div id="uboxstyle"> 
<select name="select2" id="language2"> 
<option value="">all</option> 
</select> 
</div> 
</div> 
<div style="width:100px; float:left"> 
<input type="submit" name="button" id="button" value="" style="background-image:url(images/selectbt.jpg); width:92px; height:38px; border:0px; cursor:hand;" /> 
</div> 
</form></div>