联系表单发送“空”消息?

I am trying to create a "contact us" page but once you press the "send" button, you get an empty "null" mail without any content. There is no "from", "message" or "subject" in that email and I can't find the problem.

Here is what my code looks like, contact.php:

<table width="400" border="0" align="center" cellpadding="3" cellspacing="1">
<tr>
<td><strong>Contact Form </strong></td>
</tr>
</table>
<table width="400" border="0" align="center" cellpadding="0" cellspacing="1">
<tr>
<td><form name="form1" method="post" action="send_contact.php">
<table width="100%" border="0" cellspacing="1" cellpadding="3">
<tr>
<td width="16%">Subject</td>
<td width="2%">:</td>
<td width="82%"><input name="subject" type="text" id="subject" size="50"></td>
</tr>
<tr>
<td>Detail</td>
<td>:</td>
<td><textarea name="detail" cols="50" rows="4" id="detail"></textarea></td>
</tr>
<tr>
<td>Name</td>
<td>:</td>
<td><input name="name" type="text" id="name" size="50"></td>
</tr>
<tr>
<td>Email</td>
<td>:</td>
<td><input name="customer_mail" type="text" id="customer_mail" size="50"></td>
</tr>
<tr>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td><input type="submit" name="Submit" value="Submit"> <input type="reset" name="Submit2" value="Reset"></td>
</tr>
</table>
</form>
</td>
</tr>
</table>

send_contact.php:

<?php

// Contact subject
$subject ="$subject"; 

// Details
$message="$detail";

// Mail of sender
$mail_from="$customer_mail"; 

// From 
$header="from: $name <$mail_from>";

// Enter your email address
$to ='someone@somewhere.com';
$send_contact=mail($to,$subject,$message,$header);

// Check, if message sent to your email 
// display message "We've recived your information"
if($send_contact){
echo "We've recived your contact information";
}
else {
echo "ERROR";
}
?>

Hello try to change your first line of send_contact.php

// Contact subject
$subject ="$subject"; 

// Details
$message="$detail";

// Mail of sender
$mail_from="$customer_mail";

to:

// Contact subject
$subject = $_POST['subject']; 

// Details
$message= $_POST['details'];

But i recommend you try this one: http://teachingyou.net/php/simple-php-contact-form-using-ajax/

Maybe you want something like this

$subject =$_POST['subject']; 

// Details
$message=$_POST['$detail'];

// Mail of sender
$mail_from=$_POST['customer_mail']; 

You are incorrectly defining your vars in your send_contact.php file.

$subject ="$subject"; 

Should be

$subject = $_POST['subject'];

along with your other vars. Take a look at form tutorials and POST/GET/REQUEST to better understand what's going on.