String Mismatch

[systech44]

Hi,
I have a problem. Following is my code. I would like show only those user and email from table1 whose email is not available in table2. But it is not working. I do not find my fault.

<?php

$link = mysql_connect("localhost","test","test");
mysql_select_db("test",$link);

$tab1 = mysql_query("select * from table1");
$tab2 = mysql_query("select * from table2");

$is_mail_exists = "n";
while($r1 = mysql_fetch_assoc($tab1))
{
    $user1 = $r1["name"];
    $email1 = $r1["email"];
    while($r2 = mysql_fetch_assoc($tab2))
    {
        $email2 = $r2["email"];
        if(strcmp($email1,$email2)==0)
        {
            $is_mail_exists = "y";
            break;
        }
    }
    if($is_mail_exists == "y")
        $is_mail_exists = "n";
    else
        echo $user1.", ".$email1."<br>";
}

?>

Please help. Thank you so much.