php script redirecting code problem
- by tibin mathew
hi, 
i'm using a php script for redirection after detecting the search word to my websiter from the search engines .
and my redirection code is working fine
but for some keywods i wat to stay in the same page. for that lines of code i'm getting a warning message in that pages.
Warning:  headers already sent (output started at /home/friendsj/public_html/index.php:2) in /home/friendsj/public_html/index.php on line 20
below is the code i used in that pages
$ref=$_SERVER['HTTP_REFERER'];
if(strstr($ref,"test"))
       { 
$url="http://www.howtomark.com/robgoyette.html";
   }
elseif(strstr($ref,"mu+word+gmail"))
  {
$url="http://www.howtomark.com/marketbetter.html";
}
       else
       {
       if(strstr($ref,"how+to+market+better"))
       {
   }
   }
if($url !="")
{
 header("Location:$url");
 }