webservice error 500 Internal Error asp.net

Question

I have written a webservice call in JQuery in document ready function but its not calling the function

Below is the code JQuery

`<script type="text/javascript">
$( document ).ready(function() {
var section = "Table - TLI (STOCK)";
$.ajax({
type: "GET",contentType: "application/json; charset=utf-8",
        url: "pgWebService.aspx/SliderBlock",
        dataType: "json",
        data: "{'section':'" + section + "'}",
        success: function (res) {
            //$("#Text1").val(res.text);
            console.log(res);
            alert("DONE");
        }
    });
});
</script>`

C# Code pgWebService

public static string SliderBlock(string section)
{
    string html = "<ul class='maketabs listing-table search-filter change-view'>";
    SqlConnection cn = new SqlConnection(ConfigurationManager.ConnectionStrings["TLI"].ConnectionString);
    SqlCommand cmd = new SqlCommand();
    cn.Open();
    cmd.Connection = cn;
    cmd.CommandText = "Select * from CategoryDetails where section=" + section;
    SqlDataReader rs = cmd.ExecuteReader();
    while (rs.Read())
    {
        html="<li>"+rs.getValue(0).toString()+"</li>";
    }
    rs.Close();
    cmd.Dispose();
    cn.Close();
    html = html + "</ul>";
    return html;
}

Answer 1

If your method SliderBlock is in code behind than make your method WebMethod to be called by ajax.Also you need to make it static and to be called by GET you need to enable GET requests on your WebMethod.

[System.Web.Services.WebMethod]
[System.Web.Script.Services.ScriptMethod(UseHttpGet = true)]
public static string SliderBlock(string section)
{
//Your code here
}