1.使用CommandDialog作为选择对话框
2.使用FSO对象来写文件

<OBJECT id=cDialog codeBase=
 height=0px width=0px classid=CLSID:F9043C85-F6F2-101A-A3C9-08002B2F49FB></OBJECT>
<SCRIPT language=javascript>
function SaveDocument(){
   cDialog.CancelError=true;
   try{
    cDialog.Filter="HTM Files (*.htm)|*.htm|Text Files (*.txt)|*.txt"
    cDialog.ShowSave();
    var fso = new ActiveXObject("Scripting.FileSystemObject");
    var f = fso.CreateTextFile(cDialog.filename,  true);
    f.write(document.body.innerHTML);
    f.Close();
    sPersistValue=document.body.innerHTML;}
   catch(e){
    var sCancel="true";
    return sCancel;}
  }

</SCRIPT>

<BUTTON onclick=SaveDocument();>保存</BUTTON>