5x7 DOT MATRIX DISPLAY

That tutorial is bad because there is no current limiting resistors on the LEDs, this could destroy your arduino. Do you have some in? If so what value and where?
http://www.thebox.myzen.co.uk/Tutorial/LEDs.html

i'm using a common cathode 5x7 dot matrix.

A matrix is common anode or common cathode depending on the way round you look at it.

Display do come out, but it make no sense to me

So set the code so that just one LED is to be on in a known place and see if it comes on in the place you expect it.