a better way, code technique?

[AndrewJames]

is there a better way (hopefully simpler) to code this?

i want to get the user id of the logged in user to use in my next statement.

$q1 = sprintf("SELECT uid FROM users WHERE users.username='$username'");
$result1 = mysql_query($q1);
$uid = mysql_fetch_array($result1);
$u = $uid['uid'];

it seems like a long way around to get 1 bit of data??