What is wrong with these lines of code?

[gk1993]

$u = mysql_real_escape_string($_POST["username"]);
$p = sha1($_POST["passwd"]);
$q = "SELECT * FROM profile WHERE email=`$u` AND passwd=`$p`";
$run = mysql_query($q);
  if(!$run){
    echo mysql_error();
  }

this creates Unknown column '[e-mail]' in 'where clause' error. This code is from a tutorial and a piece of a submit-new-post php page.

[ckchaudhary]

$q = "SELECT * FROM profile WHERE email=`$u` AND passwd=`$p`";

replace it with

$q = "SELECT * FROM profile WHERE email='$u' AND passwd='$p'";

[gk1993]

Thanks ckchaudhary, it solved the problem.