Thanks till for your reply
I have re-checked your 3 points and I found that I have already configured the setting of those 3 points as you mentioned .
Still have the problem ( nothing changed ) !
When I add a new site ( not a subdomain ) all the websites that are already configured in the server ( through ispconfig ) will point to that site !
Can you help me ? I am very much desperate and don't have a clue on the problem !
Thanks in advance ,