DRY principle

final.js

// Before:
// CallBacks.loadJsonView(url, "POST", Historicals.UpdateCombo, params);
// After:
$.post(url, params, Historicals.UpdateCombo, "json");

// Before:
// CallBacks.loadPartialView(url, "POST", infoDialog, params);
// After:
$.post(url, params, infoDialog, "html");

first_iteration.js

var CallBacks = (function ($) {

    var baseLoadView = function (cadurl, method, fn, datatype, params) {
            var ajaxOptions = {
                url: cadurl,
                dataType: datatype,
                contentType: "application/json",
                cache: false,
                type: method,
                success: function (data) {
                    fn(data);
                },
                error: function (XMLHttpRequest, textStatus, errorThrown) {
                    var strmsg = "Status: " + textStatus + ". Error: " + errorThrown;

                    alert(strmsg);
                }
            };

            if (typeof params !== "undefined") {
                $.extend(ajaxOptions, {
                    data: JSON.stringify(params),
                    success: function (data) {
                        fn(data, params);
                    }
                });
            }

            $.ajax(ajaxOptions);
        };

    return {
        loadJsonView: function (cadurl, method, fn, params) {
            baseLoadView(cadurl, method, fn, "json", params);
        },
        loadPartialView: function (cadurl, method, fn, params) {
            baseLoadView(cadurl, method, fn, "html", params);
        },
        loadPartialViewWithoutParams: function (cadurl, method, fn) {
            baseLoadView(cadurl, method, fn, "html");
        },
        loadJsonViewWithoutParams: function (cadurl, method, fn) {
            baseLoadView(cadurl, method, fn, "json");
        }
    };

}(window.jQuery));

original.js

var CallBacks = new function () {
    this.loadJsonView = function (cadurl, method, fn, params) {

        $.ajax({
            url: cadurl,
            data: JSON.stringify(params),
            dataType: 'json',
            contentType: 'application/json',
            cache: false,
            type: method,
            success: function (data) {
                fn(data, params);
            },
            error: function (XMLHttpRequest, textStatus, errorThrown) {
                var strmsg = "Status: " + textStatus + ". Error: " + errorThrown;

                alert(strmsg);
            }
        });
    };

    this.loadPartialView = function (cadurl, method, fn, params) {
        $.ajax({
            url: cadurl,
            data: JSON.stringify(params),
            dataType: 'html',
            contentType: 'application/json',
            cache: false,
            type: method,
            success: function (data) {

                fn(data, params);
            },
            error: function (XMLHttpRequest, textStatus, errorThrown) {
                var strmsg = "Status: " + textStatus + ". Error: " + errorThrown;

                alert(strmsg);
            }
        });
    };

	// And so on, you get the idea.
}