When a user submits an HTML form, all the data entered into the form by the user is sent as either a GET or POST request to the URL specified in the “ACTION” attribute of FORM.

<form action="http://www.labnol.org/sendmail.php" method="post">...form contents...</form>

In the above example, an HTTP POST request is issued to the sendmail.php script on form submission. You can add target=“_blank” to the FORM tag to process the request in a new window.

However, if you would like to submit a FORM on the page in the background without directing the browser to another page (document.location.href changes on form submit), you have two options:

Option #1. You can either create an invisible IFRAME inside your HTML page and set that as a target for the Original FORM. This will submit the form but without reloading the parent window.

<form action="http://example.com/script.php" method="POST" target="hidden-form">...form contents...</form>
<iframe style="display:none" name="hidden-form"></iframe>

Option #2: There’s another method that allows you create custom payloads before submitting the form. Unlike the IFRAME based form submission, the following code makes a standard form submit request and thus your browser location will change and the current page will get added to the browser history.

submitFORM('http://example.com/script.php', 'POST',
    {'name':'digital+inspiration', 'age':'100', 'sex','M'});

function submitFORM(path, params, method) {
    method = method || "post";

    var form = document.createElement("form");
    form.setAttribute("method", method);
    form.setAttribute("action", path);

    //Move the submit function to another variable
    //so that it doesn't get overwritten.
    form._submit_function_ = form.submit;

    for(var key in params) {
        if(params.hasOwnProperty(key)) {
            var hiddenField = document.createElement("input");
            hiddenField.setAttribute("type", "hidden");
            hiddenField.setAttribute("name", key);
            hiddenField.setAttribute("value", params[key]);

            form.appendChild(hiddenField);
         }
    }

    document.body.appendChild(form);
    form._submit_function_();
}