（PHP / MYSQL）致命错误：找不到类'STemplate'

my php script have this error:

Fatal error: Class 'STemplate' not found in C:\xampp\htdocs\AdultWatch\index.php on line 20

i use xampp in windows, I do not know why this error is appearing....

my index.php/config.php(inclued) File Here

You are calling assign() function of STemplate class on Line No: 67 but forgot to declare STemplate class before it.

STemplate::assign($field, strip_mq_gpc($config[$field]));

Class declaration syntax should be

$STemplate = new ClassName();