我通過js代碼對input標(biāo)簽的內(nèi)容進(jìn)行取值，可是js就是報錯說變量未定義，我檢查了好幾遍都沒檢查出到底哪里錯了，求指導(dǎo)。代碼如下      <td width="72"></td>         <td width="72">確認(rèn)密碼</td>         <td width="272"><label>             <input name="new_pwd_again" type="password"                    onkeyup="validate()"                    placeholder=" * 為必填項"                    required                    value="dsf"             />             <font name="tishi">das</font>         </label></td>js中：function validate() {    var pwd=document.getElementsByName("new_pwd_again").value;