i guess that will work too but i decided to start a new simpler one
int this one i choose a conference (the list of choices include only the conferences the user is organizing) and his choice outputs a table that shows all the authors and the reviewers for this conference.
this list of authors and reviewers have checkboxes beside them and i have to select from them which ones i want to send a message to .... basically i got most of it covered but im having problems actually sending the message to these people
i copy pasted my code but if its hard to view just let me know if i can send it to someone's email to view it properly and help me out 
i have 2 php file ... first one is where the users chooses a conference and the second is where the user chooses who recieves the message and another one that include the sending part
and again sorry for all the code i pasted 
chooseconference.php
<?php
    $con=mysql_connect('localhost','root','');
    mysql_select_db('mydb');
    $sql = "SELECT conference_id, short_name FROM conference";
    $result = mysql_query($sql);
    $num_rows=mysql_num_rows($result);
    mysql_close($con);
?>
<form name="chooseconference" action="choosepeople.php" method="POST">
    Conference: <select name="conference">
        <?php
            for($i=0;$i<$num_rows;$i++)
            {
                $conference_id=mysql_result($result,$i,0);
                $short_name=mysql_result($result,$i,1);
                echo '<option value="'.$conference_id.'">'.$short_name.'</option>';
            }
        ?>        
    </select>
    </br>
    <input type="submit" value="submit" name="submit" />
</form>
choosepeople.php
<?php
$con=mysql_connect('localhost','root','');
mysql_select_db('mydb');
//$confID = $_POST["conference"];
$confID = 1;
$query = "SELECT M.first_name, M.last_name, M.member_id
FROM Member M INNER JOIN member_privileges MP
ON M.member_id = MP.member_id
INNER JOIN privileges Pr
ON MP.privileges_id = Pr.privileges_id             
WHERE MP.conference_id = $confID 
AND Pr.role = 'author'";
echo '<form name="post" method="POST" action="viewmessages.php">';
$authors = mysql_query($query) or die(mysql_error());
 if (!$query) {echo "query error";}
if ($authors)
{   
    print "<table width=500 border=1>\n"; 
    print "<tr>\n";
    print "<th>  </th>\n"; 
    print "<th><width=\"0%\" height=\"0\" style=\"display:none\" value=\"Member ID\"</th>\n";
    print "<th> Author Name </th>\n";
     
    print "</tr>\n"; 
    //create table 
    $i = 0; 
    while ( $row = mysql_fetch_array($authors) ) { 
        $i++; 
        print "<tr>\n";
        print "<td><input type=\"checkbox\" name=\"authors[]\" value=\"$row[member_id]\"></td>\n";
        echo "<td><width=\"0%\" height=\"0\" style=\"display:none\" value=\"{$row['member_id']}\"</td>\n";
        echo "<td>{$row['first_name']} {$row['last_name']}</td>\n";
        
        echo "</tr>\n";
    }//end while    
print "</table>\n"; 
$reviewers = mysql_query("SELECT M.first_name, M.last_name, M.member_id
FROM Member M 
INNER JOIN member_privileges MP
ON M.member_id = MP.member_id
INNER JOIN privileges Pr
ON MP.privileges_id = Pr.privileges_id                
WHERE MP.conference_id = $confID
AND Pr.role = 'reviewer'") or die(mysql_error());
if ($reviewers)
{   
    print "<table width=500 border=1>\n"; 
    print "<tr>\n";
    print "<th>  </th>\n"; 
    print "<th><width=\"0%\" height=\"0\" style=\"display:none\" value=\"Member ID\"</th>\n";
    print "<th> Reviewer Name </th>\n";
     
    print "</tr>\n"; 
    //create table 
    $i = 0; 
    while ( $row = mysql_fetch_array($reviewers) ) { 
        $i++; 
        print "<tr>\n";
        print "<td><input type=\"checkbox\" name=\"reviewers[]\" value=\"$row[member_id]\"></td>\n";
        echo "<td><width=\"0%\" height=\"0\" style=\"display:none\" value=\"{$row['member_id']}\"</td>\n";
        echo "<td>{$row['first_name']} {$row['last_name']}</td>\n";
        
        echo "</tr>\n";
    }//end while    
print "</table>\n"; 
}
}
mysql_close($con);
?>  
    <div>
        <textarea name="body" rows="20" cols="110"><?php // if(isset($_POST['body']))echo htmlentities($_POST['body']); ?></textarea>
    </div>    
    <div>
        <input type="submit" value="Send" name="Send"/>
    </div>    
</form>
viewmessages.php (idk why named it that)
<?php   
$con=mysql_connect('localhost','root','');
if (!$con) {
    die ("con error");    
}
else
{
  $message=$_POST['body'];
  $x = $_POST['authors'];
  //$fulexp = implode(",", $x);
  //echo $fulexp;
  //$n = count($x);
  if( isset($x) && is_array($x))
  {
      $fulexp = implode(",", $x);
      foreach ($x as $item) 
      {
        $fulexp = implode(",", $x);
        $var = intval($item);    
        mysql_select_db('mydb');
        $re =  mysql_query("INSERT INTO member_message_member (member_id1, member_id2,conference_id, message)
                        VALUES (6, $var, 1,  $message)"); 
        ////the value 6 and 1 are defualt here no need to change now
        if (!$re) {echo "error";}
      }   
}
else {echo "didnot enter foreach";}
mysql_close($con);
}
?>