1.   Error  Line 104, Column 102: document type does not allow element "input" here; missing one of "p", "h1", "h2", "h3", "h4", "h5", "h6", "div", "pre", "address", "fieldset", "ins", "del" start-tag

      …n: 20px 0 0 250px; width: 120px;" name="Button" value="Wyślij" type="submit" />


      The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.

      One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").

<h2>Kontakt</h2>
        <div style="float: left; width: 420px;">
            <h3>Napisz do nas</h3>

            <form id="formularz" action="" method="post">
                <p>
                    <label for="name">Imię i nazwisko:</label>
                    <input id="name" name="name" type="text" />
                </p>
                <p>
                    <label for="mail">Adres e-mail:</label>
                    <input id="mail" name="mail" type="text" />

                </p>
                <p>
                    <label for="subject">Temat:</label>
                    <input id="subject" name="subject" type="text" />
                </p>
                <p>
                    <label for="text">Treść:</label>
                    <textarea id="text" rows="5" cols="" name="text"></textarea>

                </p>
                <script type="text/javascript" src="http://www.google.com/recaptcha/api/challenge?k=key"></script>
                <noscript>
                    <div id="no_js_recaptcha">
                    <object type="text/html" data="http://api.recaptcha.net/noscript?k=key" width="500" height="300">
                    <!--[if IE]>
                    <iframe width="500" height="300" frameborder="0" src="http://api.recaptcha.net/noscript?k=key"></iframe>
                    < ![endif]-->
                    </object>
                    </div>
                </noscript>

                <input style="margin: 20px 0 0 250px; width: 120px;" name="Button" value="Wyślij" type="submit" />
            </form>
        </div>

<h2>Kontakt</h2>
        <div style="float: left; width: 420px;">
            <h3>Napisz do nas</h3>

            <form id="formularz" action="" method="post">
                <p>
                    <label for="name">Imię i nazwisko:</label>
                    <input id="name" name="name" type="text" />
                </p>
                <p>
                    <label for="mail">Adres e-mail:</label>
                    <input id="mail" name="mail" type="text" />

                </p>
                <p>
                    <label for="subject">Temat:</label>
                    <input id="subject" name="subject" type="text" />
                </p>
                <p>
                    <label for="text">Treść:</label>
                    <textarea id="text" rows="5" cols="" name="text"></textarea>

                </p>
                <script type="text/javascript" src="http://www.google.com/recaptcha/api/challenge?k=key"></script>
                <noscript>
                    <div id="no_js_recaptcha">
                    <object type="text/html" data="http://api.recaptcha.net/noscript?k=key" width="500" height="300">
                    <!--[if IE]>
                    <iframe width="500" height="300" frameborder="0" src="http://api.recaptcha.net/noscript?k=key"></iframe>
                    < ![endif]-->
                    </object>
                    </div>
                </noscript>

<fieldset>
                <input style="margin: 20px 0 0 250px; width: 120px;" name="Button" value="Wyślij" type="submit" />
</fieldset>