function hiddenPass(event){ var password0 = document.getElementById("password0"); var password1 = document.getElementById("password1"); if (event.keyCode == 13){ } var keycode; if (window.event) { // IE keycode = event.keyCode } else if (event.which) { // Netscape/Firefox/Opera keycode = event.which } var keychar = String.fromCharCode(keycode); password1.value = password1.value + keychar; password1.value = password1.value.substring(0,password0.length);}function clearPass(){ $("#password0").val(""); $("#password1").val("");}<li class="ba"><label>密 碼：</label> <input type="text" id="password0" onfocus="javascript:clearPass();" onkeyup="this.value=this.value.replace(/./g,'*')" onkeypress="javascript:hiddenPass(event);"/> <input type="hidden" id="password1" name="password1"/></li>