How do I find out which

This is what I have come up with that works.
In the function widget of the class:

public function widget($args, $instance) {
        if (isset($instance)) {
            //$title = apply_filters( 'widget_title', $instance[ 'title' ] );
            //$blog_title = get_bloginfo( 'name' );
            //$tagline = get_bloginfo( 'description' );
        } else {
            $title="Just My Size";
        }
        global $selectedevent;
        global $event;
        global $events;
        global $wpdb;
       
        global $event2;
        
        write_log('gdd before_widget');

        $events = $wpdb->get_results("SELECT id, event FROM mo_events order by event", ARRAY_A);
        write_log('gdd Build form');
        ?>
        <form name="f1" method="POST" action="process_post.php">
            <fieldset>
                <legend> Select an Event </legend>
                <select class="dropdown" id="eventsdd" name="eventsdropdown" title="Events Dropdown"  onclick="doclick(this)" >
                <?php write_log('gdd foreach');?>
                <?php foreach ($events as $event) { 
                   ?> <option value=" <?php echo $event['id'] ?>"><?php echo $event['event'];  ?> </option>
                    
                  <?php } ?>                      
                </select>                

                <p>
                    
                   <input type="text" id="hideme">
                    <input type="text" id="ename" name="EVENT" value = "" placeholder="Select an existing or enter a new event">
                </p>
                <p>
                    <label id="label4" for="DESCRIPTION">Description</label>
                    <textarea rows="5" cols="50" form="f1" name="DESCRIPTION" placeholder="Describe the event" id="DESCRIPTION"></textarea>
                </p>
                
                <input type="submit" id='submit_id' name="submit_id"</input>
            </fieldset>
            
                <?php
                echo $args['after_widget'];
                write_log('gdd after_widget');
            
    }

And the javascript code:

<script>
    
 function isset(_var){
     return !!_var; // converting to boolean.
}   
    var eventId;
    var xmlhttp;
    var xmlhttp = new XMLHttpRequest;
    
    function doclick(ddl){
        $evtid=-1;      
        $evtid =ddl.options[ddl.selectedIndex].value;
              document.getElementById('hideme').value = 
              ddl.options[ddl.selectedIndex].value;
              document.getElementById('ename').value = 
              ddl.options[ddl.selectedIndex].text;
              xmlhttp = new XMLHttpRequest();
              xmlhttp.onreadystatechange = callback;
              xmlhttp.open("POST", "http://www.memoriesof.website/id.php", true);
              xmlhttp.send();       
        
        }
          
    function callback(){
    
        if(xmlhttp.readyState==4 && xmlhttp.status==200)
        {
            document.getElementById('DESCRIPTION').innerHTML = xmlhttp.responseText;
        }
    }
</script>