Ajax POST永远不会触发，既不会成功也不会出错

Question

What I am trying to do by using AJAX is when I click "Select" Button, all the related information coming from SQL DB will be assigned to the related labels. The problem is that the AJAX code below($.ajax) never gets triggered (neither success nor error). alert(res[0]) is showing the true result on screen (so the clientid parameter is true).

This is from a WebApplication Project in Asp.Net

       function BindClientSummaryForm() {
            var skillsSelect = document.getElementById('<%= ddlSFoundClients.ClientID %>');
            var selectedText = skillsSelect.options[skillsSelect.selectedIndex].text;
            var res = selectedText.split('-');
            document.getElementById('<%= hiddenClientID.ClientID %>').value = res[0];
            alert(res[0]);
            $.ajax({
                type: "POST",
                url: "Default.aspx/GetClientSummaryData",
                contentType: "application/json;charset=utf-8",
                data: "{ 'clientid': " + res[0] + "}",
                dataType: "json",
                success: function (data) {
                    alert("deneme");
                    document.getElementById('<%= lblClientNameSurnameD.ClientID %>').innerHTML = data.d.Firstname + " " + data.d.Lastname;
                    document.getElementById('<%= lblDateOpenedD.ClientID %>').innerHTML = data.d.DateFileOpened;
                    document.getElementById('<%= lblCityD.ClientID %>').innerHTML = data.d.City;
...
                },
                error: function (XMLHttpRequest, textStatus, errorThrown) {
                    alert("Error occured while filling ClientSummary part.");
                }
            });
            return false;
        }
<asp:Button runat="server" CssClass="btnSelect fieldButton" ID="btnSSelect" Text="Select"  OnClientClick="return BindClientSummaryForm()"></asp:Button>

CodeBehind

[WebMethod]
public static MyClient GetClientSummaryData(String clientid) //GetData function
{
   ...
   return client;
}

the debugger never drops to the GetClientSummaryData(clientid) method in c# as well.

I appreciate for your helps.

Answer 1

Try to change the value of content-type to text/plain on both, the client and the server , and use eval ('('+data+')') in the success function.

I know that this is not correct because the server response is json, but happened to me the same thing and I discovered (i don't know the reason) when you return the content as content-type: application/json on the server, jQuery does not call the success function.

Answer 2

What for do you specify POST as a request type? It seems like it will be more natural if you use GET (even method name tells us about that).

Also I'm not sure about this syntax data: "{ 'clientid': " + res[0] + "}" because I prefer to write scripts in separate files. Anyway, you can try to write data: { clientid: res[0] } instead