C# 定时器

  <asp:Button ID="SubmitPurchase" Text="提交采购" CausesValidation="true" Width="75px" Height="30px" runat="server" UseSubmitBehavior="false" OnClick="SubmitPurchase_Click" OnClientClick="clientClick()" CssClass="buttonSumbit" />

function clientClick()
            {
             setTimeout(function () {
                    var btn = document.getElementById(‘<%=SubmitPurchase.ClientID %>‘);
                    btn.style.display = "none";
                    setTimeout(function () {
                        btn.style.display = "";
                    }, 30000);
                }, 1000);
            }