asp.net文本框中只允许用户输入数字

<asp:TextBox ID="txtIntegralPay" runat="server" CssClass="inputtext" 

onkeypress="return event.keyCode>=48&&event.keyCode<=57||event.keyCode==46" 

onpaste="return !clipboardData.getData('text').match(/\D/)" ondragenter="return false">

</asp:TextBox>