You must give url with the variable to check, e.g:

http://example.xxx/news.php?sec=news&id=1 (valid)

http://example.xxx/news.php (invalid)

it is faster when you know how many (n)columns in the table, e.g:

order by 1,2,3,..,n (n is total columns)

leave it blank when you dont know it

use  /*   or   --  as ending

use  /**/   or   +  as space

space ending n