Help with add code for attaching a file in my PHP

Hi am newbie to PHP
I have a working code for what I want to do on my page but what I am looking for is help in how to add a function where somebody can attach a file to email to me.
PHP Code

   $errors .= "\
 Error: all fields are required";

$name = $_POST['name'];
$age = $_POST['age'];
$lastName = $_POST['last'];
$email_address = $_POST['email'];
$sex = $_POST['sex'];
$message = $_POST['message'];

if (!preg_match(
    $errors .= "\
 Error: Invalid email address";

if( empty($errors))
	$to = $myemail;
	$email_subject = "Your Lady of interest name is: $name";
	$email_body = "You have received a new message from a lovely lady. . ".
	" \
Here are the details:"."\
 My Name: $name $lastName \	 my Age is $age \
 Email: $email_address \
 Message: \
 $message \
 would you have sex on the first date: $sex";
	$headers = "From: $myemail\
	$headers .= "Reply-To: $email_address";
	//redirect to the 'thank you' page
	header('Location: contact-form-thank-you.html');
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "">
	<title>Contact form handler</title>

<!-- This page is displayed only if there is some error -->
echo nl2br($errors);



<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<title>Dating Thank message been sent</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="description" content="singles, Asians, Dating, quensland, Cairns" >
<meta name="keywords" content="Dean ,Ross, Dean Ross, Looking to date single Asians, Looking to date single Pilipino, Looking to date single Indian, Looking to date single Japanese , Dating ,girls only, Romance, Looking for a relationship, relationships, Love, lonely, singles, Dating in Queensland, Dating in Cairns, Dating Cairns, Dating Queensland, Queensland , Cairns, desperate and lonely, single men, single guys, men, guys" >
<meta name="robots" content="all" >
<meta name="robots" content="looking for - single men guys">
<meta name="revisit-after" content="15 days">
<meta name="FORMATTER" content="Dean Ross 2014">
<meta name="resource-type" content="document">
<meta name="rating" content="general">
<meta name="country" content="Australia">
<meta name="coverage" content="Australia">
<LINK rel="stylesheet" type="text/css" href="xenaStyle.css">

</head><body class="mainB" leftmargin="1" topmargin="1" bgproperties="fixed" marginwidth="0" oncontextmenu="return false">

<div id="rightMain" class="ThankYou">
 <div class="Thanks">Contact me</div>

<div id="Main" class="Main">
<td><img src="MEDean3.jpg" width="450" height="338"></td>
<td><table width="100%" border="0">
    <td class="black"><em class="black">My Height</em></td>
    <td>152 cm</td>
    <td><em class="black">My Age</em></td>
    <td>43 Years old</td>
    <td><em class="black">My Wieght</em></td>
    <td><em class="black">My build</em></td>
    <td colspan="2" >&nbsp;</td>
Please ONLY geniune Lady should message me no players!!<br>
<font class="red">Please make sure that you fill in all feild or form will fail to send</font>
<form method="POST" name="contactform" action="contact-form-handler.php">

<label for='name'>Your Name:</label>
<input name="name" type="text" size="15">
<label for='last'>Your Last name:</label>
<input name="last" type="text" size="15">
<label for='age'>Your Age:</label>
<input type="text" name="age" size="15"><br>

<label for='email'>Email Address:</label> <br>
<input name="email" type="text" size="68"> <br>

<label for='message'>Message: please leave a brief meaage about youself and some contact details</label> <br>
<textarea name="message" cols="53" rows="5"></textarea><br>
<label for="sex">would you have sex on the first date</label>
<select name="sex" id="sex">
	<option value="Yes - if it felt right at the time.">Yes - if it felt right at the time.</option>
    <option value="No- Please do not askme again">No- Please do not askme again</option>

<label for='photo'> Please upload a Photograph</label>
    <label for='photo' >Upload your photo:</label><br/>
     <span id='contactus_photo_errorloc' class='error'></span>   <input type="file" name='photo' id='photo' />

<input type="submit" value="Send Email"> <input type="reset" value="Reset Form"><br>


<script language="JavaScript">
// Code for validating the form
// Visit
// for details
var frmvalidator  = new Validator("contactform");
frmvalidator.addValidation("name","req","Please provide your name");
frmvalidator.addValidation("email","req","Please provide your email");
frmvalidator.addValidation("email","email","Please enter a valid email address");


You need to add Content-Type: multipart/alternative; with mixed boundary hash.