e-mail validation

[vietboy505]

I need help on the e-mail form to work, can any one help me?

I want the form to check if everything is inputs correct such as an valid e-mail.

<?php

function determineEmail($Purpose)
{
        if($Purpose == "General") {
                $mailTo="Name1 <[e-mail]>, Name2 <[e-mail]>";

    } elseif($Purpose == "Customer") {
            $mailTo="Name2 <[e-mail]>, Name3 <[e-mail]>";
    } else {
    //proably won't be in here
            $mailTo="[e-mail]";
    }
}

if(!preg_match("/^([0-9a-zA-Z]([-.w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-w]
*[0-9a-zA-Z].)+[a-zA-Z]{2,9})$/",$_POST["Email"])) {
//email address is invalid
die("Invalid Email");
}

if(!empty($message)){ // only send if the form has been filled out.
  $mailHeaders="From : $Name [$Email]";
  $mailSubject="$Purpose from $Name";
  $mailBody="Sent by $Name ($Email) on " . date('M j,Y h:i:s') . " \n\n";
  $mailBody.="Message : \n\n $message";

  mail($mailTo, $mailSubject, $mailBody, $mailHeaders);
  echo "<b>Your email has been sent!</b><br>";
}


echo('<form name="email_form" method="post">
<input type="hidden" name="require" value="Name,Email,Purpose,Comments">
<table>
<tr>
    <td align="right">Name:</td>
    <td><input name="Name" size="25"></td>
</tr>

<tr>
    <td align="right">E-mail:</td>
    <td><input name="Email" size="25"></td>
</tr>
<tr>
    <td align="right">Purpose:</td>
    <td><select name="Purpose">
    <option value="General">General
    <option value="Customer">Customer
    </select>
    </td>
</tr>

<tr>
    <td align="right">Comments:</td>
    <td><textarea name="Comments" rows="10" cols="40"></textarea>
    </td>
</tr>

<tr>
    <td colspan="2" align="center"><input type="submit" value="Submit" name="ema
il_form">
    <input type="reset" value="Reset" name="reset"></td>
</tr>
</table>
</form>');
?>