two mysql queries

[narendra vuppuluri]

i have to accomplish two tasks. and i want to do that in single query if possible.

task 1: i have to find out the maximum value of the column "id" and generate a random number between 1 and value from above.

task 2: use the random number in another query.

Can somebody please solve this.
i have written these seperate queries.

1 :

$query = "select MAX(id) from phpvar_in_mysqlquery";
$result = mysqli_query($dbc,$query) or die('error querying database');
$row = mysqli_fetch_array($result);
$number = rand(1,$row['MAX(id)']);

2 :

$query = "select * from phpvar_in_mysqlquery where id = $number";
$result = mysqli_query($dbc,$query) or die('error querying database');
$row = mysqli_fetch_array($result);
echo $row['id'].'<br />';

i have grabbed the maximum value in the first query and generated a random number.
i used the random number in the second query.