callAjax(url, paramsInsert, true, function (data) {
    if (data.success) {
        modal("OK", "<h3>ALL OK</h3>", "OK");
    } else {
        modal("error", "<h3> ERROR </h3>", "Error");
    }
});

function callAjax(url, parametros, load, funcion) {

if (load) {
    var element = document.createElement("div");
    element.id = "loadBackground";
    element.className = "backLoad";
    document.body.appendChild(element);
    document.getElementById("contenido").innerHTML = '<div class="loadImage"><div class="col-xs-12 col-sm-12 col-md-12"><div class="col-xs-4 col-sm-4 col-md-4"></div><div class="col-xs-4 col-sm-4 col-md-4"><img class="center-block" src="img/ajax-loader.gif" /></div><div class="col-xs-4 col-sm-4 col-md-4"></div></div></div>';
}

var ajax = new XMLHttpRequest();

ajax.onreadystatechange = function () {
    if (ajax.readyState === 4) {
        //var datos = JSON.parse(ajax.responseText);

        var jsontext = ajax.responseText;

        var content = eval('(' + jsontext + ')');
        //if (content.success) {
        funcion(content);
        if (load) {
            document.getElementById("contenido").innerHTML = '';
            document.body.removeChild(document.getElementById("loadBackground"));
        }
        // }

    }
};
ajax.open("POST", url, true);
ajax.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
ajax.send(parametros);