Here is the code.... The code is suppose to display a chat room and it's messages. The error message is Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource

$Name = $_SESSION['Name'];
$Post_ = $_POST['post'];
$Insert = mysql_query("INSERT INTO Chat
(Name, Text) VALUES ('$Name', '$Post_')");
$View_Chat = mysql_query("SELECT * FROM Chat");

if($Insert == "")
{
//nothing
}

echo "<table border='1'>
<tr>
<th>My Posts</th>
<th>Latest Posts</th>
</tr>";

while($row = mysql_fetch_array($Insert))
{
echo "<tr>";
echo "<td>" . $row['myposts'] . "</td>";
echo "<td>" . $row['latestposts'] . "</td>";
echo "</tr>";
}
echo "</table>";

?>