PHP Chatbox : Cannot Send to MySQL Database - php

Question

Code :
$user = $_POST["user"];
$message = $_POST["message"];
$message = htmlspecialchars($message);
$db=mysqli_connect("host","username","pwd","db");
if (mysqli_connect_errno()){
echo "Failed to connect to MySQL: " . mysql_connect_error();
}
#Connected
if(isset($message) == true && $message != "" && $message != " "){
if(isset($user) == false){
$user = "visitor";
}
$sql="
INSERT INTO ChatBox (DateTime, User, Content)
VALUES
(now(),'$_POST[User]','$_POST[Content]')
";
if (!mysqli_query($db,$sql))
{
die('Error: ' . mysqli_error($db));
}
}
mysqli_close($db);
This is my code in a chatbox.
However, I use the line if(isset($message) == true && $message != "" && $message != " "){ to find out whether $_POST['message'] is null or not.
Finally, I cannot insert anything in my chat box.
This is my chatbox link : http://jamie-is-cool.comeze.com/chat.php
The problem is that : After clicking Send! nothing happened. It just reload and didn't send.
What should I do?
A complete list of code is available here.

Answer 1

Insert code block will on fire if the statement if( isset( message) ... returns a true.
But in your HTML form, there is no such element with name message but a user and content.
<form action="chat.php" style="margin:0px;padding:1px;" method="POST">
User: <input type="text" style="width:15%;" name="User" /> |
<input type="text" style="width:65%;" name="Content" />
<input type="submit" value="Send!" style="width:10%;" />
</form>
Add an input type element named message to the form with some value and then submit to get succeed.
<form action="chat.php" style="margin:0px;padding:1px;" method="POST">
User: <input type="text" style="width:15%;" name="User" /> |
<input type="text" style="width:65%;" name="Content" />
<input type="text" style="width:65%;" name="message" />
<input type="submit" value="Send!" style="width:10%;" />
</form>
For better display, adjust the form table display width accordingly.