how to avoid the Refresh in MasterPage in ContentPage

[StA1L3r]

I have a masterpage with a timer that shows server time and refreshes every second, on the content page I have a chat program with ajax, refreshes every to second to get the last messages entered.I have a Html TextBox and a hidden Submit Button, when user write a text, and hit the enter, I check to see if this is the enter key and then submit the message,it is working perfectly in IE, but in FireFox and Opera it show the same message twice.I think the problem is the Timer, is there any way to avoid the MasterPage timer in this particular content page?Thanks in advance