This is your original code with minor modification and I have added coments where appropriate.
<?
$DJgroup=$_POST["DJgroup"];
$eventdate=$_POST["eventdate"];
$Promotername=$_POST["Promotername"];
$venuename=$_POST["venuename"];
$venuelocation=$_POST["venuelocation"];
$contactemail=$_POST["contactemail"];
$extrainfo=$_POST["extrainfo"];
$TheTitle="BOOKINGS";
$ClientMemoContent="Please select your required DJ or Artist: ".$DJgroup."\neventdate (d/m/y): ".$eventdate."\nPromoter / company name: ".$Promotername
."\nClub / venuename: ".$venuename."\nWhere is your venue located ? ".$venuelocation."\nYour contactemail address: ".$contactemail
."\nextrainformation: ".$extrainfo;
$message ="
<html>
<head>
<title>BOOKINGS</title>
</head>
<body>
<p><b>BOOKINGS</p>
<p ><b>Below is the information filled out by a client.</p>
<table>
<tr>
<td width=300>Please select your required DJ or Artist: </td><td>".$DJgroup."</td>
</tr>
<tr>
<td>eventdate (d/m/y): </td><td>".$eventdate."</td>
</tr>
<tr>
<td>Promoter / company name:</td><td>".$Promotername."</td>
</tr>
<tr>
<td>Club / venuename:</td><td>".$venuename."</td>
</tr>
<tr>
<td>Where is your venue located ?</td><td>".$venuelocation."</td>
</tr>
<tr>
<td>Your contactemail address:</td><td>".$contactemail."</td>
</tr>
<tr>
<td>extrainformation:</td><td>".$extrainfo."</td>
</tr>
</table>
</body>
</html>
";
$headers = "MIME-Version: 1.0\r\n";
$headers .= "Content-type: text/html; charset=gb2312\r\n";
$headers .= "To: admin@something.net, artist@somesite.com>\r\n";//added for artist you will need you email here
$headers .= "From:$contactemail\r\n";
$result=mail("admin@something.net",$TheTitle,$message,$headers);//Need your email address here too to test
if($result)
{
?>
<script language='javascript'> alert('message sent');location.href='thankyou.html'; </script>
<?
}
else
{
?>
<script language='javascript'> alert('message failed');window.history.back();; </script>
<?
}
?>
File in your email where needed, then you will need to have a group of artists and their email address when selected say from a frop down box and entered as $artist or $_POST['artist'] but you need a form so I made one foryou to test the script with and also made a quickie little thankyou.html required by the above code after the email has sucessfully been sent. Here is the form
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
<head>
<title>Test Form</title>
</head>
<body bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<form action="newtestform.php" method="POST" enctype="application/x-www-form-urlencoded">
<table border=1 width=100%><tr><td>
<input type="text" name = "DJgroup" />Enter a DJ Group.<br />
</td>
<td>
<input type="text" name ="eventdate" />Please enter the date for the event.<br />
</td>
</tr>
<td>
<input type="text" name ="Promotername" />Enter the promoter name.<br />
</td>
<td>
<input type="text" name ="venuename" />Enter the venue for the event.<br />
</td>
</tr>
<td>
<input type="text" name ="venuelocation" />Enter the venues location.<br />
</td>
<td>
<input type="text" name ="contactemail" />Enter a contact e-mail address.<br />
</td>
</tr>
<tr>
<td colspan=2 width=100%>
Any additional information should be entered in the textarea below such as directions and
other <br />contact e-mails or phone numbers, bad dogs running loose, war zones in the area etcetera.<br />
<textarea name= "extrainfo" cols="70" rows="15" wrap="auto"></textarea>
</tr></table>
<input type="submit" value="Continue" name="artist"/>
</form>
</body>
</html>
Last of all you need a tankyou.html, so here is a cheap quick one.
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
<head>
<title>Thank you</title>
<meta http-equiv="generator" content="PHP Designer 2006 - BETA" />
</head>
<body bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<h1><center>Thank You</h1></center>
Your information has been sent to the proper people and you will be contacted soon. Thank you
for takeing the time to fill out the form and also for choosing us to provide the service
you want for your event.
</body>
</html>
