Returns part of haystack string from the first occurrence of needle to the end of haystack.
If needle is not found, returns FALSE.
If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
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.
strstr() has been binary safe since PHP 4.3.0