mysql_num_rows(): supplied argument is not a valid MySQL result resource in /user/690

[delite]

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /data/9/0/24/113/676928/user/690291/htdocs/inc/_up_index1.php on line 40

This is the error i get every time when any of my php scripts try to read/write in my mysql data base.

This is _up_index1.php

<?

$test_act['new_tranzaction']="OK";



$test_act['tranzaction_details_started']="OK";

$test_act['tranzaction_details_pointing']="OK";

$test_act['accept_tranzaction']="OK";

$test_act['reject_tranzaction']="OK";

$test_act['tranzaction_details']="OK";

$test_act['payment']="OK";

if(!$test_act[$act]){

$act="tranzactions";
}



if(session_is_registered("valid_user")){

$act=$act;}

else{

$errormsg="";

if($do=="login"){

$sql="select * from escrow_user where user='$user' and pass=PASSWORD('$pass') LIMIT 1";

$result=mysql_query("$sql");

$n=mysql_num_rows($result);    /// LINE 40

if($n==0){

$errormsg="Invalid Log In";

$title="LOG IN";

$act="login";}

else{

$rand=mysql_fetch_array($result);

$valid_user=$user;

$valid_email=$rand[email];

session_register("valid_user");

session_register("valid_email");

$title="your account";

$act=$act;}

}

else{$act="login";

$title="LOG IN";

}

}

?>

I am a newbie in php so if anyone can help me fix this website it will be highly apreciate.

thanks

[rcasinillo_s]

Try this im sure it will work...
$sql="select * from escrow_user where user='$user' and pass='$pass' LIMIT 1";