<body> <table> <tr><td colspan=2 align="left"><select id="fsDrivers" onchange="ChangeDrive(this)"><option>--请选择驱动器--</option></select></td></tr> <tr><td valign="top"><select id="fsFolders"><option>---请选择目录---</option></select></td><td valign="top"><select size=20 id="fsFiles" style="width:200px;"></select></td></tr> </table> </body> <script> function $(id) { return (id.constructor == String) ? document.getElementById(id) : id; } function ChangeDrive(t) { var index = t.selectedIndex; if (index == 0) { var temp = document.createElement('OPTION'); temp.innerText = '---请选择目录---'; var o = $('fsFolders'); o.innerHTML = ''; o.appendChild(temp); } else { var tmp = t.options[index].value + '\\\\'; var a = ShowFolderList(tmp); var o = $('fsFolders'); o.innerHTML = ''; for(var i=0; i<a.length; i++) { var op = document.createElement('OPTION'); op.value = a[i]; op.innerText = a[i]; o.appendChild(op); } } } function ShowFolderList(folderspec) { var fso, f, fc, a; fso = new ActiveXObject("Scripting.FileSystemObject"); f = fso.GetFolder(folderspec); fc = new Enumerator(f.SubFolders); a = new Array; for (; !fc.atEnd(); fc.moveNext()) { a[a.length] = fc.item(); } return(a); } function getDrives() { var fso, a, n, e, x; fso = new ActiveXObject("Scripting.FileSystemObject"); e = new Enumerator(fso.Drives); a = new Array; for (; !e.atEnd(); e.moveNext()) { x = e.item(); a[a.length] = x.DriveLetter; } return(a); } var a = getDrives(); var o = $('fsDrivers'); for(var i=0; i<a.length; i++) { var op = document.createElement('OPTION'); op.value = a[i] + ':'; op.innerText = a[i] + ':'; o.appendChild(op); } </script> [提示：你可先修改部分代码，再按运行]
运行时，由于浏览器的安全设置，会出现以下提示：
