PHP Post Echo Two Sql Entries - php

Question

I need help figuring out why I receive two entries into my database with the following code. At this time it is inputting the complete record and a blank record into the database. Not sure why. Can anyone point me in the right direction of where I am going wrong? Thanks.
Form and PHP Code
<form method="post" action="cu.php">
<input type="text" name="name" value size="35"
placeholder="Name">&nbsp&nbsp
<input type="text" name="email" value size="35" placeholder="Email">
<br><br>
<select name="dropdown">
<option value="0">Comment Type</option>
<option value="A">Accounting</option>
<option value="FAQ">FAQ</option>
<option value="GQ">General Question</option>
<option value="TS">Technical Support</option>
</select>
<br><br>
<textarea name="comments" rows="10" cols="60" style"border: 3px solid #555"
placeholder="Comments"></textarea>
<br><br>
<input type="submit" value="Submit" id="btn">
<input type="reset" value="Reset" id="btn">
</form>
</one>
</div>
<?php
if ($_POST) {
$name = $_POST['name'];
echo "User Has submitted the form and entered this name : <b>$name</b>";
echo "<br>You can use the following form again to enter a new name.";
}
$con = mysql_connect("mysql", "username", "pswd");
if (!$con) {
die('Could not connect: ' . mysql_error());
}
/* Prevent duplicate submissions */
if (isset($_COOKIE['FormSubmitted'])) {
show_error('You may only submit this form once per session!');
}
mysql_select_db("communication", $con);
$sql = "INSERT INTO contact (name, email, cusno, dropdown, comments)
VALUES
('$_POST[name]', '$_POST[email]', '$_POST[cusno]', '$_POST[dropdown]',
'$_POST[comments]')";
if (!mysql_query($sql, $con)) {
die('Error: ' . mysql_error());
}
mysql_close($con);

Answer 1

That is because, everytime the page load, php will run your sql insert code. This happen because you don't check if the form is submitted, then run the sql query.
Do like this:
add name to your submit button:
<input type="submit" value="Submit" id="btn" name="submit">
then in php, wrap the sql insert in if statement
// check if submit button is POST, then run query
if(isset($_POST['submit']))
{
$sql = "INSERT INTO contact (name, email, cusno, dropdown, comments)
VALUES
('$_POST[name]', '$_POST[email]', '$_POST[cusno]', '$_POST[dropdown]',
'$_POST[comments]')";
if (!mysql_query($sql, $con)) {
die('Error: ' . mysql_error());
}
}

Answer 2

Update this lines
if (!mysql_query($sql, $con)) {
die('Error: ' . mysql_error());
}
to
if (!empty($_POST) && !mysql_query($sql, $con) ) {
die('Error: ' . mysql_error());
}
Also i suppose that you browser requesting favicon file and the fore your code can be executed twice