JS实现选择文件保存路径

<script>
functionbrowseFolder() {    
    try{    
        varMessage = "请选择路径";  //选择框提示信息    
        varShell = newActiveXObject("Shell.Application");    
        varFolder =Shell.BrowseForFolder(0, Message, 64, 17);//起始目录为：我的电脑     
        //var Folder = Shell.BrowseForFolder(0,Message,0); //起始目录为：桌面
        if(Folder != null) 
        {    
            Folder =Folder.items();  //返回 FolderItems 对象    
Folder =Folder.item();  //返回 Folderitem 对象    
Folder =Folder.Path;   //返回路径    
            if(Folder.charAt(Folder.length - 1) != "\") 
            {    
                Folder =Folder + "\";    
            }    
            //document.getElementById(path).value = Folder;   
document.getElementById("show").value=Folder;
            //alert(Folder);    
            returnFolder;    
        }    
      }    
      catch(e) 
     {    
        alert(e.message);    
     }    
}  

</script>