Use this function to submit an HTML form without actually having a form on the page. Instead of an existing form, pass the function a *flat* JavaScript object with the form values to submit. This is a synchronous operation; the browser loads the response as its new window location. Requests with "Content-Type: application/x-www-form-urlencoded".

submitForm.js

var submitForm = function(config) {

    if (!config) {
        throw new Error();
    }
    else {
        config.method = config.method || 'post';
        config.data = config.data || {};
        config.url = config.url || (function() { 
            throw new Error('Missing required `url` argument');
        })();
    }
    
    this.createElement = function(tag, attrs) {
        var el = document.createElement(tag);
        Object.keys(attrs).forEach(function(key) {
            el.setAttribute(key, attrs[key]);
        });
        return el;
    };
    
    var form = this.createElement('form', {
        method: config.method,
        action: config.url
    });

    function add(name, value) {
        if (typeof value === 'undefined') {
            return;
        }
        else if (value === null) {
            value = 'null';
        }
        
        form.appendChild(this.createElement('input', {
            type: 'hidden',
            value: value,
            name: name
        }));
    }
    
    Object.keys(config.data).forEach(function (key) {
        var value = config.data[key];

        if (Array.isArray(value)) {
            value.forEach(function (v) {
                add(key, v);
            });
        }
        else if (Object.prototype.toString.call(value) === '[object Object]') {
            throw new TypeError('`data` members cannot be objects.');
        }
        else {
            add(key, value);
        }
    });
    
    form.submit();
};

var url = 'http://www.google.com';

// Request body: datetime=1365811679443&guids=C20H32O2&guids=C43H66N1
submitForm({ 
    url: url,
    data: {
        datetime: Date.now(),
        guids: [
            'C20H32O2', 
            'C43H66N1'
        ]
    }
});

// Request body: 0=C20H32O2&1=false&3=null&4=Fri+Apr+12+2013+17%3A21%3A33+GMT-0700+%28Pacific+Daylight+Time%29&5=1
submitForm({ 
    url: url, 
    data: [
        'C20H32O2',
        false,
        undefined,
        null,
        new Date(),
        1
    ]
});

// Empty request body
submitForm({
    url: url, 
    data: {}
});

// Empty request body
submitForm({
    url: url
});

// intentionally throws TypeError
submitForm({
    url: url, 
    data: {
        winner: {
            id: 0
        }
    }
});

// intentionally throws Error
submitForm({
    url: undefined, 
    data: {
        custId: 0
    }
});

// intentionally throws Error
submitForm(undefined);

// GET http://www.google.com/?datetime=1366211074394&guids=C20H32O2&guids=C43H66N1 with no request body
submitForm({
    url: url,
    method: 'get',
    data: {
        datetime: Date.now(),
        guids: [
            'C20H32O2', 
            'C43H66N1'
        ]
    }
});