How to store a drop down list value to variable before submit

Question

I want to find a way to store the selected option from dropdown list before the submit. so i can handle it to the form input value.

Im new to php.

Thanks in advance.

I tried to use this $katigoriaselected=$_POST['options'];

and store the selected item to <input type='hidden' name='katigoriaslc' value='$katigoriaselected'>

                if(isset($_SESSION['userID'])){
                    $onoma = $_SESSION['username'];
                    $mnpstusrid = $_SESSION['userID'];

          echo "<form method='POST' action='".setPosts($conn)."'>
                <input type='hidden' name='mainpstuserid' value='$mnpstusrid'>
                <input type='text' name='pstTittle'  placeholder='Τιτλος Δημοσιευσης'><br><br>
                <p>ΚΑΤΗΓΟΡΙΕΣ<br>
                <select name='options'>
                <option value='Astia'>ΑΣΤΕΙΑ</option>
                <option value='Tainies'>ΤΑΙΝΕΙΕΣ</option>
                <option value='anim'>ANIME</option>
                </select><br>
                $katigoriaselected=$_POST['options'];           
                <input type='hidden' name='mainpostusername' value='$onoma'>
                <input type='hidden' name='date' value='".date('Y-m-d H:i:s')."'>
                <textarea name='mainpost'></textarea><br>
                <button name='usrmainpostsubmit' type='submit' class='mainpstbutton1'>Post</button>
                </form>";
                }
                ?>```

the error message :

```Parse error: syntax error, unexpected '' (T_ENCAPSED_AND_WHITESPACE), expecting '-' or identifier (T_STRING) or variable (T_VARIABLE) or number (T_NUM_STRING)```

Answer 1

It seems that i was doing my job harder wo a reason it's pointless to store the variable to sth when you dont need to. I could just send it straight to my function controller. I didnt know u can pass <select name='options'> (from index.php) to $katigoria = $_POST['options']; .(to myfunction.php).