Mysql problems - Mysql fetch array and adding to database

Hi I have two mysql problems

a) I'm confused on why this code won't add data to my database:

$con = mysql_connect("localhost","username","password");
mysql_select_db("database", $con);

$sql="INSERT INTO Table ('adder', 'username')
VALUES('$myusername','$username1')";
mysql_query( $sql, $con ) or trigger_error( mysql_error( $con ), E_USER_ERROR );

here is the full error: "you have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'Add (username, name, number) VALUES('56', 'Name', 'number')' at line 1"

and before you ask, yes the data is there

b) I'm having problems with mysql_fetch_array

This is the code:

mysql_connect("$host", "$mysqlusername", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB");

$sql = "SELECT * FROM Add WHERE adder=\"$username\"";
$result=mysql_query($sql);
$row=mysql_fetch_array($result);
if (empty($row)) {
echo "$username hasn\'t added anyone";
}
else {
while($row = mysql_fetch_array($result)){
echo "<a href=\"/".$row[username]."><".$row[username]."</a>"; 
}
}

The error here is: Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in....

And yes the data is there on the database aswell..

Any ideas??

Thanks for the help :) Niall