Pass the text in <label> tag in form to PHP
<p>I'm trying to pass the value (text) I have in label tag in HTML5 to my PHP so I can use that value in subject of the email. There are two buttons and none of them gonna have any input from user. everything is going to be automatic. Sorry about the mess. I also attached a picture. 
<a href="https://i.stack.imgur.com/vMdis.jpg" rel="nofollow noreferrer">This is a screenshot of what im trying to do</a></p>

<p><strong>php</strong></p>

<pre><code>&lt;?php
    $demo = $_POST['demo_name'];

    // Create the email and send the message
    $to = 'soroush@hotmail.ca'; // Add your email address inbetween the '' replacing yourname@yourdomain.com - This is where the form will send a message to.
    $email_subject = "Client:  $demo";
    $email_body = "START";
    $headers = 'From: soroush.report@gmail.com'; // This is the email address the generated message will be from. We recommend using something like noreply@yourdomain.com.
    //$headers .= "Reply-To: $email_address";   
    mail($to,$email_subject,$email_body);
    return true;    

    if (mail($to,$email_subject,$email_body)) {
        echo 'Sent';
    }
    else {
        echo 'Not sent';
    }       
?&gt;
</code></pre>

<p><strong>html</strong></p>

<pre><code>&lt;html&gt;
&lt;head&gt;
    &lt;!-- Contact Form CSS files --&gt;
    &lt;style&gt;
    body {
        padding: 20px;
    }

    button {
        margin-top: 20px;
        margin-right: 10px;
        line-height: 60px;
        font-weight: bold;
        padding: 0 40px;
        background: highlight;
        color: #FFFFFF;
        border: none;
    }

    button:hover {
        background: red;
    }

    .button {
        display: inline-block;
        border-radius: 4px;
        background-color: Highlight;
        border: none;
        color: #FFFFFF;
        text-align: center;
        font-size: 28px;
        padding: 10px;
        width: 150px;
        transition: all 0.5s;
        cursor: pointer;
        margin: 5px;
    }

    .button span {
        cursor: pointer;
        display: inline-block;
        position: relative;
        transition: 0.5s;
    }

    .button span:after {
        content: '»';
        position: absolute;
        opacity: 0;
        top: 0;
        right: -20px;
        transition: 0.5s;
    }

    .button:hover span {
        padding-right: 25px;
    }

    .button:hover span:after {
        opacity: 1;
        right: 0;
    }

    .hide {
        display: none;
    }
    &lt;/style&gt;

    &lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"&gt;&lt;/script&gt;
    &lt;script type="text/javascript"&gt;
    // Your Client ID can be retrieved from your project in the Google
    // Developer Console, https://console.developers.google.com
    var CLIENT_ID = 'MY CLIENT ID FROM GOOGLE API CALENDER';
    var SCOPES = ["https://www.googleapis.com/auth/calendar.readonly"];

    /**
    * Check if current user has authorized this application.
    */
    function checkAuth() {
        gapi.auth.authorize({
            'client_id': CLIENT_ID,
            'scope': SCOPES.join(' '),
            'immediate': true
            }, handleAuthResult);
    }

    /**
    * Handle response from authorization server.
    *
    * @param {Object} authResult Authorization result.
    */
    function handleAuthResult(authResult) {
        var authorizeDiv = document.getElementById('authorize-div');
        if (authResult &amp;&amp; !authResult.error) {
            // Hide auth UI, then load client library.
            authorizeDiv.style.display = 'none';
            loadCalendarApi();
        } else {
            // Show auth UI, allowing the user to initiate authorization by
            // clicking authorize button.
            authorizeDiv.style.display = 'inline';
        }
    }

    /**
    * Initiate auth flow in response to user clicking authorize button.
    *
    * @param {Event} event Button click event.
    */
    function handleAuthClick(event) {
        gapi.auth.authorize(
            {client_id: CLIENT_ID, scope: SCOPES, immediate: false},
            handleAuthResult);
        return false;
    }

    /**
    * Load Google Calendar client library. List upcoming events
    * once client library is loaded.
    */
    function loadCalendarApi() {
        gapi.client.load('calendar', 'v3', listUpcomingEvents);
    }

    /**
    * Print the summary and start datetime/date of the next ten events in
    * the authorized user's calendar. If no events are found an
    * appropriate message is printed.
    */
    function listUpcomingEvents() {
        var request = gapi.client.calendar.events.list({
            'calendarId': 'primary',
            'timeMin': (new Date()).toISOString(),
            'showDeleted': false,
            'singleEvents': true,
            'maxResults': 10,
            'orderBy': 'startTime'
        });

        request.execute(function(resp) {
            var events = resp.items;
            appendPre('Upcoming events:');

            if (events.length &gt; 0) {
                for (i = 0; i &lt; events.length; i++) {
                    var event = events[i];
                    var when = event.start.dateTime;

                    if (!when) {
                        when = event.start.date;
                    }
                    appendPre(event.summary + ' (' + when + ')');
                }
            } else {
                appendPre('No upcoming events found.');
            }

            function initButtons() {
                for (j = 0; j &lt; events.length; j++) {
                    var body = document.body, button, j;
                    // ntahoang: event is declared and assigned here:
                    var event = events[j];
                    (function (j) {
                        button = document.createElement("button");
                        button.innerHTML += event.summary;
                        button.value = event.summary;

                        button.addEventListener("click", function (e) {
                            var x = document.createElement("STRONG");
                            var t = document.createTextNode(this.innerHTML);
                            x.appendChild(t);
                            document.getElementById("demo").appendChild(x);

                            //alert(this.innerHTML);
                        }, false);

                        body.appendChild(button);
                    }(j));
                }
            } initButtons();
        });
    }

    function appendPre(message) {
        var pre = document.getElementById('output');
        var textContent = document.createTextNode(message + '\n');
        pre.appendChild(textContent);
    }
    &lt;/script&gt;
    &lt;script src="https://apis.google.com/js/client.js?onload=checkAuth"&gt;&lt;/script&gt;
&lt;/head&gt;

&lt;body&gt;
    &lt;div id="authorize-div" style="display: none"&gt;
        &lt;span&gt;Authorize access to Google Calendar API&lt;/span&gt;
        &lt;!--Button for the user to click to initiate auth sequence --&gt;
        &lt;button id="authorize-button" onclick="handleAuthClick(event)"&gt;
            Authorize
        &lt;/button&gt;
    &lt;/div&gt;
    &lt;pre id="output"&gt;&lt;/pre&gt;

    &lt;form action="../email/start.php" method="POST"&gt;
        &lt;label id ="demo"&gt;Client: &lt;/label&gt;
        &lt;input type="hidden" id="test"/&gt;
        &lt;input class="button" style="vertical-align:middle" id="start" type="submit" value="Start"/&gt;
        &lt;input class="button" style="vertical-align:middle" id="start" type="submit" value="Finish" /&gt;
    &lt;/form&gt;

    &lt;form action="action_page.php"&gt;
        &lt;textarea name="message" rows="30" placeholder="Please write your report..." cols="75"&gt;&lt;/textarea&gt;
        &lt;br&gt;
        &lt;button class="button" type="submit"&gt;Report&lt;/button&gt;
    &lt;/form&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre>