服务器控件调用JavaScript

<asp:Button ID="uxButtonSubmit" class="button" runat="server" Text="确定" OnClientClick="return CheckValue();" OnClick="uxButtonSubmit_Click" />

<script type="text/javascript">
    function CheckValue()
    {
        var oldPwd = $("<%=uxTextBoxOldPwd.ClientID %>").value;
        var newPwd = $("<%=uxTextBoxNewPwd.ClientID %>").value;
        var checkPwd = $("<%=uxTextBoxCheckPwd.ClientID %>").value;
       
        if(oldPwd == "")
        {
            showMsg("请输入旧密码");
            return false;   
        }
        if(newPwd == "")
        {
           showMsg("请输入新密码");
           return false;
        }
        if(checkPwd=="")
        {
           showMsg("请您确认新密码");
           return false;
        }
        if(checkPwd!=newPwd)
        {
           showMsg("请您确认两次输入的密码一致");
           return false;
        }
        return true;
    }
    </script>