Why do I use PHP code to insert data into MySQL displayed as empty

Why do I use PHP code to insert data into MySQL displayed as empty
Why do I use PHP code to insert data into a MySQL field where some fields appear to be empty and the inserted values can appear my code is as follows


Include ("conn.php");

if ($_post[' submit ']) {

$sql = "INSERT into message (id,user,title,content,lastdate)".
"Value (' ', ' $_post[user] ', ' $_post[title] ', ' $_post[content] ', now ())";
mysql_query ($sql);
echo "Publishing Success";
}
?>



The contents of the phpMyAdmin.
ID User Title Content lastdate
1 One of my titles for my PHP 2012-04-15
2 _ My content for your PHP 2012-04-15





------Solution--------------------
mysql_query ($sql) or Die (Mysql_error ());
Come up with the results!
Maybe you don't know what's going on.
------Solution--------------------
Do you have any questions about values?
------Solution--------------------
User:

Text is wrong.

