asp.net客户端OnClientClick方法

OnClientClick方法真乃神器，客户端方法，和服务器端的onclick时间不冲突。

<asp:Button ID="btnLogin" runat="server" Text="登录" Height="26px" onclick="btnLogin_Click" OnClientClick="return Check()" Width="68px" />

function Check() {
             var name = document.getElementById("txt_user_num").value;
             var pwd = document.getElementById("txt_user_pwd").value;
             var code = document.getElementById("tbcode").value;
             if (name == "" || pwd == "" || code == "") {
                 document.getElementById("txt_user_num").style.backgroundColor = "Red"
                 return false;
             }else{ 
                return true
             }