在模态中插入查询

I would like to ask for some assistance when it comes to inserting details into mysql database if data are inside a modal. I have been trying to complete this sample project of mine hoping that I can use it as a portfolio in the future. Here's the modal code.

main.php

<div class="modal fade" id="registrationModalold" role="dialog">
  <div class="modal-dialog">
  <!-- Modal content-->
    <div class="modal-content">
      <!--<form action="functions/actions.php" method="POST">-->
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal">&times;</button>
          <h4 class="modal-title">Enrollment Details</h4>
      </div>
      <div class="modal-body">
        <form method="post" action="functions/actions.php">
          <h4 class="modal-title">Personal Information</h4>
          <div class="row">
          <div class="col-lg-6 col-xs-6">
            <label for="usr">Name:</label>
            <select class="form-control" name="courses">
            <?php 
              include 'ini/db.php'; //connect to database
              $sql = "SELECT distinct student_name FROM tbl_students";
              $res = mysqli_query($conn,$sql);
              echo "<option>---SELECT STUDENT---</option>";

              while ($row = mysqli_fetch_array($res)){
                echo "<option value=Course".$row['student_name'].">" . $row['student_name'] . "</option>";
              }
            ?>
            </select>
          </div><!-- ./col -->
          <div class="col-lg-6 col-xs-6">
            <label for="usr">Addres:</label>
            <input type="text" class="form-control" id="fullname">
          </div><!-- ./col -->
        </div>
        <div class="row">
          <div class="col-lg-3 col-xs-6">
            <label for="usr">Contact:</label>
            <input type="text" class="form-control" id="fullname">
          </div><!-- ./col -->
          <div class="col-lg-3 col-xs-6">
            <label for="usr">BirthDate:</label>
            <input type="text" class="form-control" id="fullname">
          </div><!-- ./col -->
          <div class="col-lg-3 col-xs-6">
            <label for="usr">Birth Place:</label>
            <input type="text" class="form-control" id="fullname">
          </div><!-- ./col -->
          <div class="col-lg-3 col-xs-6">
            <label for="usr">Gender:</label>
            <select class="form-control">
              <option id="male">Male</option>
                <option id="female">Female</option>
            </select>
          </div><!-- ./col -->
        </div>
        </br></br>
        <h4 class="modal-title">Other Information</h4>
          <div class="row">
            <div class="col-lg-6 col-xs-6">
              <label for="usr">Course:</label>
                <select class="form-control" name="courses">
                <?php 
                  include 'ini/db.php'; //connect to database
                  $sql = "SELECT crs_id,crs_name FROM tbl_courses";
                  $res = mysqli_query($conn,$sql);
                  echo "<option>---SELECT COURSE---</option>";

                  while ($row = mysqli_fetch_array($res)){
                    echo "<option value=Course".$row['crs_id'].">" . $row['crs_name'] . "</option>";
                  }
                ?>
                </select>
              </div><!-- ./col -->
              <div class="col-lg-6 col-xs-6">
                <label for="usr">Major:&nbsp<font color="red" size="2"><i>optional</i></font></label>
                <input type="text" class="form-control" id="fullname">
              </div><!-- ./col -->
            </div>
            <div class="row">
              <div class="col-lg-3 col-xs-6">
                <label for="usr">Mother's Name:</label>
                <input type="text" class="form-control" id="fullname">
              </div><!-- ./col -->
              <div class="col-lg-3 col-xs-6">
                <label for="usr">Mother's Occupation:</label>
                <input type="text" class="form-control" id="fullname">
              </div><!-- ./col -->
              <div class="col-lg-3 col-xs-6">
                <label for="usr">Father's Name:</label>
                <input type="text" class="form-control" id="fullname">
              </div><!-- ./col -->
              <div class="col-lg-3 col-xs-6">
                <label for="usr">Father's Occupation:</label>
                <input type="text" class="form-control" id="fullname">
              </div><!-- ./col -->
            </div>
          </div>
        <div class="modal-footer">
          <button name="btnregister" action="functions/actions.php" type="button" class="btn btn-default">Save</button>
          <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
         </div>
       </form>
     </div>
   </div>
 </div>
</div>

As you can see there's a button there a button which points to my actions.php which is inside another folder which is functions folder. But when I click that nothing happens.

Here's the action.php:

if (isset($_POST['btnregisters'])) {
    echo "ASASASASASASASASASASAS";
    die("asdsadsada");
}

As you can see there's a button there a button which points to my actions.php which is inside another folder which is functions folder. But when I click that nothing happens

<button name="btnregister" action="functions/actions.php" type="button" class="btn btn-default">Save</button>

You said type="button". The entire point of that is to make the button do nothing (so you can bind JavaScript event handlers to it).

Take that out and let it be the default (type="submit") which would submit the form.

Please see that the submit button is set as button type = "button"

 <button name="btnregister" action="functions/actions.php" type="button" class="btn btn-default">Save</button>

Change it to:

<button name="btnregister" action="functions/actions.php" type="submit" class="btn btn-default">Save</button>

You have already defined action attribute in form tag. action attributes are not for buttons so do not write it there.

To submit a form you need a submit button so, change type of your save button from "button" to "submit" it should be like

<button name="btnregister" type="submit" class="btn btn-default">Save</button>