@ Tony Valko

We create a list with all the sheets and Named it as "List"

Then i used this formula.

 =SUMPRODUCT(SUMIF(INDIRECT("'"&List&"'!$B$5:$b$1000"),$B5,INDIRECT("'"&List&"'!c$5:c$1000 ")))
..It seems that folks use the file attachment option a lot here!
Yes this is true. For me(as i don't speak English very well) is the best way to understand the point!

Nice to see here Tony! I have learned a lot from you.