This Function should extract the keyword from the referrer URL to get what your visitor was searching for on google, msn, live, altavista, alltheweb, scirus, aol, vivisimo, lycos, aliweb, yahoo and baidu.
function getKeywordfromRef($orgWord){
$ref = $_SERVER['HTTP_REFERER'];
if( preg_match("#(google|msn|live|altavista|alltheweb|scirus)#si", $ref)){
$s=explode("?",$ref);
parse_str($s[1]);
return $q;
}elseif(preg_match("#(aol|vivisimo|lycos|aliweb)#si", $ref) ){
$s=explode("?",$ref);
parse_str($s[1]);
return $query;
}elseif(strstr( $ref,'yahoo')){
$s=explode("?",$ref);
parse_str($s[1]);
return $p;
}elseif(strstr( $ref,'baidu')){
$s=explode("?",$ref);
parse_str($s[1]);
return $wd;
}else
return $orgWord;
}
you can send a default keyword in case the visitor was not coming from a search engine or just set $orgWord = ”
to call the function
$myKeyword = getKeywordfromRef($myKeyword)