C# 定时器

<asp:Button Text="提交采购" CausesValidation="true" 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);
}