$.fn.disable = function() {
 return this.each(function() {
     if (typeof this.disabled != "undefined") this.disable = true;
 });
}

<script type="text/javascript">
    $.fn.disable = function() {
 //擴展jQuery，表單元素統一disable
 return this.each(function() {
     if (typeof this.disabled != "undefined") this.disabled = true;
 });
    }
    $.fn.enable = function() {
 //擴展jQuery，表單元素統一enable
 return this.each(function() {
     if (typeof this.disabled != "undefined") this.disabled = false;
 });
    }

    function SwapInput(oName, oButton) {
 if (oButton.value == "Disable") {
     //如果按鈕的值為Disable，則調用disable()方法
     $("input[name=" + oName + "]").disable();
     oButton.value = "Enable";
 } else {
     //如果按鈕的值為Eable，則調用enable()方法
     $("input[name=" + oName + "]").enable();
     oButton.value = "Disable"; //然后設置按鈕的值為Disable
 }
    }
</script>
<form method="post" name="myForm1" action="addInfo.aspx">
    <p>
 <label for="name">請輸入您的姓名:</label>
 <br>
 <input type="text" name="name" id="name" class="txt">
    </p>
    <p>
 <label for="passwd">請輸入您的密碼:</label>
 <br>
 <input type="password" name="passwd" id="passwd" class="txt">
    </p>
    <p>
 <label for="color">請選擇你最喜歡的顏色:</label>
 <br>
 <select name="color" id="color">
     <option value="red">紅</option>
     <option value="green">綠</option>
     <option value="blue">藍</option>
     <option value="yellow">黃</option>
     <option value="cyan">青</option>
     <option value="purple">紫</option>
 </select>
    </p>
    <p>請選擇你的性別:
 <br>
 <input type="radio" name="sex" id="male" value="male">
 <label for="male">男</label>
 <br>
 <input type="radio" name="sex" id="female" value="female">
 <label for="female">女</label>
    </p>
    <p>你喜歡做些什么:
 <input type="button" name="btnSwap" id="btnSwap" value="Disable" class="btn" onclick="SwapInput('hobby',this)">
 <br>
 <input type="checkbox" name="hobby" id="book" value="book">
 <label for="book">看書</label>
 <input type="checkbox" name="hobby" id="net" value="net">
 <label for="net">上網</label>
 <input type="checkbox" name="hobby" id="sleep" value="sleep">
 <label for="sleep">睡覺</label>
    </p>
    <p>
 <label for="comments">我要留言:</label>
 <br>
 <textarea name="comments" id="comments" cols="30" rows="4"></textarea>
    </p>
    <p>
 <input type="submit" name="btnSubmit" id="btnSubmit" value="Submit" class="btn">
 <input type="reset" name="btnReset" id="btnReset" value="Reset" class="btn">
    </p>
</form>

jQuery.noconflict();