Email send problem

Warning: mail() [function.mail]: "sendmail_from" not set in php.ini or custom "From:" header missing in C:\Domains\sachalsoft.com\wwwroot\nabibux\index1.php on line 9
I m facing the above error when try to run the code to send email
please visit this url where i place the code

http://nabibux.sachalsoft.com/index1.php
where i put the script to
see my smtp server info
http://nabibux.sachalsoft.com/index.php
by usiing above link you can see the configuration of sever where i host my site
i dont have permission to chage any thing in the sever now please tell how i send mail using php script
i have the following code

<?php

$to_addr = 'nabibux@sachalsoft.com';

if (isset($_REQUEST['submit'])) {
$mail_body = 'Name: '.$_REQUEST['name'];
$mail_body .= "\nEmail: ".$_REQUEST['email'];
$mail_body .= "\nMessage: ".$_REQUEST['message'];
mail($to_addr,'Form Feedback',$mail_body);
print "Thank you for the feedback.";
} else {
print<<<_HTML_
<form method="POST" action="$_SERVER[PHP_SELF]">
<table>
<tr><td>Name:</td><td><input type="text" name="name"></td></tr>
<tr><td>Email:</td><td><input type="text" name="email"></td></tr>
<tr><td>Message:</td><td><textarea name="message"></textarea></td></tr>
<tr><td colspan="2"><input name="submit" type="submit"></td></tr>
</form>
_HTML_;
}

?>

Thanks please help

 

Try adding...

ini_set ("sendmail_from","a.body@acompany.com");

to force the From header before calling the mail function.

 

Thanks for help i got it now thanks tooooo