I am sorry for off-topic, I am considering about making an interesting site for pupils. Will possibly commence with publishing interesting facts just like"Mexico City sinks about 10 inches a year"Please let me know if  you know where I can find some related information like here
 
http://stevenrgerst.com/o41-jy/09/articles-nydpoPL-1024/function.include
http://stevenrgerst.com/247-gy/00/articles-nydpoFS-5794/function.include/page/function.session-start