如何处理jqueryajax帖子的结果

asp:CustomValidator

<script language="javascript" type="text/javascript">
function ValidateInput(source, args) {
    if($('#MyTxtBox').val().length > 0) {
        var result;
        var webMethod = 'http://domain/webservice.asmx/ValidateInput';
        var parameters = "{'input':'" + $('#MyTxtBox').val() + "'}";

        $.ajax({
            type: "POST",
            url: webMethod,
            data: parameters,
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function(msg) {            
                args.IsValid = msg.d;
            }
         });
    }
    else {
        args.IsValid = false;
    }
}
</script>
<asp:TextBox ID="MyTxtBox" runat="server" />
<asp:CustomValidator ID="cvCreditCardNumber" runat="server" ClientValidationFunction="ValidateCCNumber" Display="Dynamic" 
ErrorMessage="&nbsp;Please enter valid input." />

Web服务代码

[WebMethod]
[ScriptMethod(ResponseFormat=ResponseFormat.Json)]
public bool ValidateInput(string input)
{
    if(input.Equal("jQuery is awesome!"))
        return true;
    else
        return false;
}