Simple news script

[Pino]

$host="localhost";
$user="me";
$password="you";
$database="hello";


      $connection = mysql_connect($host,$user,$password)or die ("Error Conecting To DB");
      $db = mysql_selectdb($database,$connection) or die ("bad table\db data");

      $query = "SELECT * FROM tblnews";
      $result = mysql_query($query);

      $nrows = mysql_num_rows($result);
      
      for ($i=0;$i<$nrows;$i++)
      {
        $row = mysql_fetch_array($result);
        echo $row;
      }
      

?> 

and the error i am getting is

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in path/index.php on line 15

Any ideas on how to fix this?

also if i just wanted to select 3 coloums from the db how would i put my query


$query = "SELECT one two three FROM tblnews"; would that be right?