面对ajax中的错误

i get error message [object Object] - error - Internal Server Error when using ajax to call asp.net web method. i wan to get list of object from the server with the ajax.

ajax code

var Packages;
$.ajax({
type: "POST",
async: false,
url: "http://localhost:54954/WebSite/B/Setting/Packages.asmx/GetAllPackage",
data: "{}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (response) {
Packages = response.d;
},
error: function (XMLHttpRequest, textStatus, errorThrown) {
alert(XMLHttpRequest.toString() + ' - ' + textStatus + ' - ' + errorThrown);
}
});

web method code

public class Package
{
    public float PackageId;
    public string Code;
    public string Name;
}
[WebMethod]
public List<Package> GetAllPackage() {
    List<Package> PackageList =new List<Package> {};

    for (int i = 1; i <= 100; i++)
    {
        var temp = new Package();
        temp.PackageId = i;
        temp.Code = "Code " +  i;
        temp.Name = "Name" + i;
        PackageList.Add(temp);
    }

        return PackageList;
}

may i know which part i had make the mistake??

Several places.. for starters your WebMethod does not return JSON

I suggest reading this: - What are some simple and fast ways to retieve session variables using javascript or jquery?