Code in Main Timeline - buttons not working

Ok - think the beer killed a few brain cells - need help…

I got a flash file which am coding in AS2.0 and all code on the main timeline.

Within a movieclip there is a button on the timeline which I can access from the main timeline, i.e.

KPI_mc.new_btn.onRelease = function(){

This then goes onto another part of the timeline with another button called ‘save’. But the following code doesn’t work. Is there anything I need to do for it to be accessable from the main timeline?

KPI_mc.save_btn.onRelease = function(){
KPI_1 = KPITitle;
KPI_1Desc = KPIDesc;

//move on to the menu screen


If I put the save button by the ‘new’ button it works… Any help?