function createListFolder(siteUrl, listName, foldername) {

    var serverUrl = _spPageContextInfo.webAbsoluteUrl;

    $.ajax({

        url: serverUrl + "/_api/Web/Folders/add('"+listName+"/"+ foldername+"')",

        type: "POST",

        headers: {

            "accept": "application/json; odata=verbose",

            "content-type": "application/json; odata=verbose",

            "X-RequestDigest": $("#__REQUESTDIGEST").val()

        },

        error: function (data) {

            alert(data.responseText);

            //alert("fail");

        }

    });

}