Select Department <font color='red'>*</font> </b> <?php
    $con=mysqli_connect("localhost","username","password","database_name");
    if (mysqli_connect_errno())
    {
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }
    $result1 = mysqli_query($con,"SELECT * FROM dept");
    echo "<select>";
    while($drop = mysqli_fetch_array($result1))
    {
    echo "<option>" . $drop['department'] . "</option>";
    }
    echo "</select>";
    mysqli_close($con);
    ?>

<form class="appnitro"  method="post" action="">
    <div class="form_description">
    <center><h2>NOMINATE ENTRY</h2></center>
    <p></p>
    </div><center>
    <b>Department &nbsp &nbsp </b> <?php
    $con=mysqli_connect("localhost","username","password","dbname");
    if (mysqli_connect_errno())
    {
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }
    $result1 = mysqli_query($con,"SELECT * FROM dept");
    echo "<select name='department'>";
    while($drop = mysqli_fetch_array($result1))
    {
    echo "<option value='".$drop['department']."'>" . $drop['department'] . "</option>";
     }
    echo "</select>";
    mysqli_close($con);
    ?><p></center>
    <ul><center>
    <li class="buttons"><button type="submit" formaction="echo.php">Go</button></center></li>
    </ul>
    </form>

Department &nbsp &nbsp : <?php session_start(); $result=$_SESSION['department']; echo " ". $result;  ?>

Select Department <font color='red'>*</font> </b>


    <form name ="form1" action="" method="post"> /* You can remove this if you already have a form */
    <?php
    $con=mysqli_connect("localhost","username","password","database_name"); // replace for you own.
    if (mysqli_connect_errno())
    {
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }
    $result1 = mysqli_query($con,"SELECT * FROM dept");
    echo "<select name='department_name'>";
    while($drop = mysqli_fetch_array($result1))
    {
    echo "<option value='".$drop['department']."'>" . $drop['department'] . "</option>"; /* I would recommend changing the $drop['department'] in to the primary key from your table dept for example $drop['id'] */
     }
    echo "</select>";
    mysqli_close($con);
    ?>
    <input type="submit" value="Submit" name="submit">
    </form>
    <?php
    IF(isset($_POST['submit'])){
    echo "<b>Selected department: </b>".$_POST['department_name'] ;
    } /* This a test to see if you dropdown list works.  */
    ?>

CREATE TABLE dept (
  id int auto_increment primary key,
  department varchar (30)
  );

INSERT INTO dept (department)
VALUES ('department foo'), ('department foobar');

<form action="myfile.php" method="post">
<select name="mydropdown">
<option value="a">A</option>
<option value="b">B</option>
</select>

<input type="submit" value="Submit">
</form>

<?php

$x = $_POST['mydropdown'];

?>

<form class="appnitro"  method="post" action="">
<div class="form_description">
<center><h2>NOMINATE ENTRY</h2></center>
<p></p>
</div><center>
<b>Department &nbsp &nbsp </b> <?php
$con=mysqli_connect("localhost","username","password","dbname");
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$result1 = mysqli_query($con,"SELECT * FROM dept");
echo "<select name='department'>";
while($drop = mysqli_fetch_array($result1))
{
echo "<option value='".$drop['department']."'>" . $drop['department'] . "</option>";
 }
echo "</select>";
mysqli_close($con);
?><p></center>
<ul><center>
<li class="buttons"><button type="submit" formaction="echo.php">Go</button></center>
</li>
</ul>
</form>

<h3>Department &nbsp &nbsp : <?php $dept = $_POST['department']; echo " ". $dept; ?> </h3>