Action Script 2.0 to 3.0 CS4 Flash

[andy_nic]

We have upgraded from MX2004 to CS4 & When I try to convert my code to Action script from 2.0 to 3.0, My buttons for my menu disappear and sometimes it tells me my code is wrong the code for the action script is
"stop();
Year11_BTN.onRelease = function() {
gotoAndStop("Year 11");
stop();
Year12_BTN.onRelease = function() {
gotoAndStop("Year 12");"
"etc.
am i missing something?