IN operator with 2 tables

Question

I am try to get result from 2 tables but its done but when I use IN operator with 2 different WHERE statement its bring result from only 1 table.

May I know where I am mistake?

$search_Query = "SELECT * FROM `sys1`,`sys2` WHERE sys1.id_1 IN (705,1,7,706,707) AND sys2.id_2 IN (705,1,7,706,707)";    
    $search_Result = mysqli_query($conn, $search_Query);        
    if($search_Result){
        if(mysqli_num_rows($search_Result)){
            while($row = mysqli_fetch_array($search_Result)){
                    $finddown = $row['display_name']; //from sys1.id_1
                    $stream_status = $row['status']; // from sys2.id_2

                     echo $finddown. " = " . $cstatus;
            }