asp有象VB的combo控件一样的可以手动修改内容的下拉框码？解决办法

asp有象VB的combo控件一样的可以手动修改内容的下拉框码？
asp有象VB的combo控件一样的可以手动修改内容的下拉框码？或者类似的对象

[解决办法]
ComboBox.js

function getLeftPostion( theObj )
{
var pos = 0;
while ( theObj != null )
{
pos += theObj.offsetLeft;
//get the Object which contain theObj.
theObj = theObj.offsetParent;
}
return pos;
}
function getTopPostion( theObj )
{
var pos = 0;
while ( theObj != null )
{
pos += theObj.offsetTop;
//get the Object which contain theObj.
theObj = theObj.offsetParent;
}
return pos;
}
function checkVersion()
{
var isBadVersion=true;
var curVer=navigator.appVersion;
var pos=parseInt(curVer.indexOf( "MSIE "));
if (pos> =1)
{
var intVer=parseInt(curVer.charAt(pos+5));
if (intVer> =5)
{ isBadVersion=false;}
}
if (isBadVersion)
{
var msg= "This page may not be displayed properly:\n "+
" This product requires Microsoft Internet Explorer 5 or later browser only. ";
alert(msg);
}
}

//check the browser version
checkVersion();

// the array of comboBoies
theArray = new Array();

function combobox(objId, objHandler)
{
this.comObj = document.all[objId];
this.comObj.selectedIndex = -1;
this.getValue = getValue;
this.doResize = doResize;
this.doChange = doChange;
this.loseFocus = loseFocus;
this.doSelectIdx = doSelectIdx;
this.focus = focus;

var strMsg= " ";

//------------------------------------------------------------------
// create the text object
//------------------------------------------------------------------
var txtObjIdName = objId + "_text ";

if (document.all[txtObjIdName] != null)
{
strMsg= "The following id: ' " + txtObjIdName + " ' is used internally by the Combo Box!\r\n "+
"Use of this id in your page may cause malfunction. Please use another id for your controls. ";
alert(strMsg);
}

var txtInner = " <INPUT type= 'text ' id= " + txtObjIdName + " name= " + txtObjIdName +
" onblur= ' " + objHandler + ".loseFocus() ' " +
" style= 'display: none; position: absolute ' value= ' ' > ";

this.comObj.insertAdjacentHTML( "afterEnd ", txtInner);

this.txtObj = document.all[txtObjIdName];
//------------------------------------------------------------------
// end
//------------------------------------------------------------------

this.beResizing = false;
this.doResize();
theArray[theArray.length] = this;
}

function loseFocus()
{
var theComObj = this.comObj;
var theTxtObj = this.txtObj;
var i;
theComObj.selectedIndex = -1;

if (theTxtObj.value == " ")
{ return; }

var optLen = theComObj.options.length;
for (i=0; i <optLen; i++)
{
var comVal = theComObj.options[i].text;
var txtVal = theTxtObj.value;

if (comVal == txtVal)
{ theComObj.selectedIndex = i;
return;
}
}
}

function doResize()

{
if (!this.beResizing)
{
this.beResizing = true;
this.txtObj.style.display= "none ";
this.comObj.style.position= "static ";
this.txtObj.style.posLeft = getLeftPostion(this.comObj);
this.txtObj.style.posTop = getTopPostion(this.comObj) + 1;
this.txtObj.style.posWidth = this.comObj.offsetWidth - 16;
this.txtObj.style.posHeight = this.comObj.offsetHeight;
this.comObj.style.position = "absolute ";
this.comObj.style.posLeft = this.txtObj.style.posLeft;
this.comObj.style.posTop = this.txtObj.style.posTop;
this.offWidth = this.comObj.offsetWidth;
var strRect = "rect(0 "+(this.comObj.offsetWidth)+ " "+ this.comObj.offsetHeight +
" "+(this.txtObj.style.posWidth - 2 )+ ") ";

this.comObj.style.clip = strRect;
this.txtObj.style.display= " ";
this.beResizing = false;
}
}

function doChange()
{
var idx = this.comObj.selectedIndex;
var opt = this.comObj.options[idx];
this.txtObj.value = opt.text;
this.txtObj.focus();
this.txtObj.select();
this.comObj.selectedIndex=-1;
}

function getValue()
{ return this.txtObj.value; }

function doSelectIdx(i)
{
var optLen = this.comObj.options.length;

if ((i > =0) && (i < optLen))
{ this.comObj.selectedIndex = i;
this.txtObj.value = this.comObj.options[i].text;
return;
}

this.txtObj.value = " ";
}


function focus()
{ this.txtObj.focus(); }

/* resize all combobox when window be resized */
function resetAllSize()
{
var i;
for (i=0; i < theArray.length; i++)
{
theArray[i].doResize();
}
}