以下控件，显示错误验证信息以后，怎么样让textbox控件清空内容

Question

<asp:Label ID="Label1" runat="server" Text="姓名：" Height="20px" Width="80px" ></asp:Label>

<asp:TextBox ID="TextBox1" runat="server" Height="20px" Width="150px"></asp:TextBox>

<asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ErrorMessage="请输入中文" ControlToValidate="TextBox1" ValidationExpression="^[\u4e00-\u9fa5]+$" Display="Dynamic" ></asp:RegularExpressionValidator>