FormPost.js

// Arguments :
//  verb : 'GET'|'POST'
//  target : an optional opening target (a name, or "_blank"), defaults to "_self"
window.io = {
    open: function (verb, url, data, target) {
        var form = document.createElement("form");
        form.action = url;
        form.method = verb;
        form.target = target || "_self";
        if (data) {
            for (var key in data) {
                var input = document.createElement("textarea");
                input.name = key;
                input.value = typeof data[key] === "object"
                    ? JSON.stringify(data[key])
                    : data[key];
                form.appendChild(input);
            }
        }
        form.style.display = 'none';
        document.body.appendChild(form);
        form.submit();
        document.body.removeChild(form);
    }
};

function openWithPost(data) {
    io.open('POST', data.Message,
        {
            SymmetricToken: data.SymmetricToken,
            AsymmetricToken: data.AsymmetricToken
        });
}