The code will look something like this :
$msg = "Your mail message will be here.";
$subj = "Mail Subject";
//The Header is generated only if you have html tags in the $msg. Otherwise you may even omit this parameter.
$headers = "Content-type: text/html; charset=iso-8859-1\r\n";
$headers .= "From: Alexander <$from>\r\n";
mail ($to,$subj,$msg, $headers);
Hope this helps U !!!