Can't login to my own forum, that sucks

[Toxicous8]

I'm unable to login? plz help

 
session_start();
include_once ('dbconnect.php');


if(isset($_POST['log'])) {
	$dbselect = mysql_query("USE codb");
	$uname = mysql_real_escape_string($_POST['username']);
	$upass = mysql_real_escape_string($_POST['pass']);
	$sql = mysql_query("SELECT * FROM users WHERE username=".$uname." AND password=".$upass." LIMIT 1");
	$res = mysql_query($sql);
	
	
	if(mysql_num_rows($res) == 1) {
		$row = mysql_fetch_assoc($res);
		$_SESSION['user'] = $row['user_id'];
		header("Location: speak.php");
	}else{
		$error = error_reporting(E_ALL^E_WARNING);
		echo "<script>alert('Wrong details!');</script>";
	}
	
}

It displays

 
Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\log.php on line 14

[RonB]

Your mysql_query($sq l)statement failed i.e., it returned FALSE. Add error checking/handling to that statement to find out why it failed.

Hint, you have a syntax (quoting) error in the query.

[Toxicous8]

Error checking and handling? what is it?
And where's the quoting error please? tnx

[Toxicous8]

Error checking and handling? what is it? If it's like

$error = error_reporting();

, then i don't see how it would be useful to fix this problem. If not then what is it?

And where's the quoting error please? tnx