Thank you for your reply.
Your code for number formating works fine.
About continue shopping button I have to say, that your solution also works - after clicking the button I am redirected to tab from which I came.
But now another problem occurred (just in Firefox, not IE, another browsers dont know):
When I for example add in cart some product, click continue shopping button so I am returned to starting tab (so far everything ok), than click directly on Cart tab - in this case Firefox shows my cart as empty. It shows my added product just after I click browsers refresh button.
I would appreciate your help also in this matter.