引用JS文件后验证控件失效的问题


<head runat="server">
    <title>Employee修改</title>
    <script type="text/javascript" language="javascript" src="JS/setday.js" />
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <table>
        <tr><th colspan="3" align="left">Employee修改</th></tr>
        <tr>
            <td>姓名</td><td><asp:TextBox ID="TxtEmployeeName" runat="server"/></td>
            <td><asp:RequiredFieldValidator ID="RfvEmployeeName" runat="Server" ErrorMessage="姓名必填" Text="姓名必填" ControlToValidate="TxtEmployeeName" /></td>            
        </tr>
        <tr>
            <td>性别</td><td><asp:RadioButton ID="RbtnMan" runat="server" Text="男" GroupName="EmployeeSex" /><asp:RadioButton ID="RbtnWoman" runat="server" Text="女" GroupName="EmployeeSex" /></td>
            <td></td>
        </tr>
        <tr>
            <td>年龄</td><td><asp:TextBox ID="TxtEmployeeAge" runat="Server" /></td>
            <td><asp:RegularExpressionValidator id="RevEmployeeAge" runat="server" ErrorMessage="年龄必须为数字" ControlToValidate="TxtEmployeeAge" Text="年龄必须为数字" ValidationExpression="\d{1,2}"/></td>
        </tr>
        <tr>
            <td>注册日期</td><td><asp:TextBox ID="TxtEmployeeRegTime" runat="Server" onclick="setday(this)" /></td>
            <td><asp:RegularExpressionValidator ID="RevEmployeeRegTime" runat="server" ErrorMessage="注册日期格式错误" Text="注册日期格式错误" ControlToValidate="TxtEmployeeRegTime" ValidationExpression="^((((1[6-9]|[2-9]\d)\d{2})-(0?[13578]|1[02])-(0?[1-9]|[12]\d|3[01]))|(((1[6-9]|[2-9]\d)\d{2})-(0?[13456789]|1[012])-(0?[1-9]|[12]\d|30))|(((1[6-9]|[2-9]\d)\d{2})-0?2-(0?[1-9]|1\d|2[0-8]))|(((1[6-9]|[2-9]\d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))-0?2-29-))$" /></td>
        </tr>
    </table>
    </div>
    </form>
</body>
</html>
<script type="text/javascript" language="javascript" src="JS/setday.js" />
这段代码引用外部的JS/setday.js文件，只要引用了外部js文件,Asp.Net的验证控件就会无效，也不出现错误提示