php application problem+HTML

Dear all,

I have two problems,
1).I want to prevent enter one Supvisor number ='$Sup_Emp_No' by two
different supordinates ='$Sub_Emp_No' into the system.

2).How can incorporate HTML CODES to the $message of the mail function.I am
using "wamp5" for this application.

Can you help me please.


<?php
session_start();
if(!isset($_SESSION["Emp_No"])||!isset($_SESSION["Dep_Name"])||!isset($_SESSION["User_Level"])||!isset($_SESSION["Email"])||!isset($_SESSION["First_Name"]))
{
header("Location:./error.php");
}

$empid =$_SESSION['epf_no'];
$dbhost='localhost';
$dbuser='root';
$dbpass='';
$dbname='metrosite';



if(isset($_POST["Submit"])){
$perc = $_POST["total"];
$comments = $_POST["comments"];
$Sub_Emp_No = $_POST["Sub_Emp_No"];
$Sup_Emp_No = $_POST["Sup_Emp_No"];
//$sup_no = $_POST["sup_no"];


$conn = mysql_connect($dbhost,$dbuser,$dbpass)or die (mysql_error());
mysql_select_db($dbname, $conn) or die (mysql_error ());

$sql = "INSERT INTO sub_app ( Sub_Emp_No , Sup_Emp_No , Perc , Comments )
VALUES ( '$Sub_Emp_No', '$Sup_Emp_No', '$perc', '$comments');";

if(!mysql_query($sql,$conn)){

$mess =mysql_errno($conn);
if($mess=="1062"){
$mess = "Entry was already entered !";
}
else {
echo "error <br>";
echo mysql_error($conn);
}
}
else{
$mess = "Successfully entered !";
}
{
$query1 = "SELECT * FROM emp WHERE Emp_No= '$Sub_Emp_No'";
$query2 = "SELECT * FROM emp WHERE Emp_No= '$Sup_Emp_No'";
$stmnt ="SELECT * FROM emp ";
$result = mysql_query($query1,$conn);
$row1 = mysql_fetch_assoc($result);
$from = $row1["Email"];

$result2 = mysql_query($query2,$conn);
$row2 = mysql_fetch_assoc($result2);
$to = $row2["Email"];

//$result3=mysql_query($query2,$conn);
//$row3 = mysql_fetch_assoc($result3);



//$mess = "Entry was already entered !";


switch ($row1["User_Level"]) {
case 1 :
case 2 :
case 3 :
$r = mysql_query($stmnt,$conn);
while($object =mysql_fetch_object($r)){
if($object->User_Level == 4 && $object->Dep_Name==$row1["Dep_Name"]){
$to=$object->Email;
break;
}
}
break;
case 5 :
$to = "ceo@wasantha.lk";
break;
case 6 :
$to = "nimal@wasantha.lk";
break;

}

$subject ="Employee ".$row1["First_Name"]." evaluated you on Subordinate's
angle.";
$message = "<strong>Subordinate evaluation percentage is:"
.$perc.".</strong>rnrnYou may see your Overall evaluation by clicking
the 'Whole summary' on your pagernrnBut wait till you finish your
appraisal discussion with your superior(Dept. Head) and Peer's evaluation on
you where you will get an e-mail message.rnrn rn rn Best regards,
rn HR Dept. rn";


//mail($to,$subject,$message)
//or print "Could not send mail";
$headers = 'From:'.$from. "rn" .
'Reply-To:'.$to."rn" .
'X-Mailer: PHP' . phpversion();
mail($to,$subject,$message, $headers)
or print "Could not send mail";
}
mysql_close($conn);

}

?>


regards
wasantha