$word=array('word1','word2');
$string='word word word word1 word1222 word323 word2';
 if (strstr($word[1],$string)) {
   print "$word[1]!";
 }
 if (strstr($word[2],$string)) {
   print "$word[2]!";
 }
 /******************************/
 if (preg_match("/$word[1]|$word[2]/i",$string)) {
   print 'results!!!'; 
 }