http://php.net/rtrim
Description
string rtrim ( string str [, string charlist])
Note: The second parameter was added in PHP 4.1.0
This function returns a string with whitespace stripped from the end of str. Without the second parameter, rtrim() will strip these characters:
" " (ASCII 32 (0x20)), an ordinary space.
"\t" (ASCII 9 (0x09)), a tab.
"\n" (ASCII 10 (0x0A)), a new line (line feed).