Translation Please?

Just between us gals, when you have to go to the washroom, you have to go.

Now....as many know...I am a rule follower.  I head to the washroom at the cafe where we had lunch and this is the sign, on the women's washroom door.

I wanted to do the right thing.  But I don't understand the instructions.  I understand it will cost 100 Hungarian forint.  About 50 cents.  But what about the rest?  It appears to be more words than are needed.

I go back to Deb and ask for some change to go pee.

I head back.  Where does it go?  There is no one around.

Well....I go pee.....and on the outside of the door, that I didn't notice, was a coin box for the use of the water closet.

Rough translation "The toilet using cost 100 ft.  For our guests."