string strstr ( string $haystack , mixed $needle [, bool $before_needle = false ] )
Returns part of haystack string from the first occurrence of needle to the end of haystack. Note: This function is case-sensitive. For case-insensitive searches, use stristr(). Note: If you only want to determine if a particular needle occurs within haystack, use the faster and less memory intensive function strpos() instead.
Returns the portion of string, or FALSE if needle is not found.