Well your problem is that you never defined the Prototype that the script calls on from your button.
On your frame you have an action that says something that makes absolutely not sense… that would be this line…
getURL("on (release) {
getURL(\"javascript:newWin('pic_show.html','imageGallery','280','315','0','0')\");
}");
Now, I removed that line, because there was no point to it and I added this in there…
Movieclip.prototype.openWinCentre = function(url, winName, w, h, toolbar, location, directories, status, menubar, scrollbars, resizable) {
getURL("javascript:var myWin; if(!myWin || myWin.closed){myWin = window.open('"+url+"','"+winName+"','"+"width="+w+",height="+h+",toolbar="+toolbar+",location="+location+",directories="+directories+",status="+status+",menubar="+menubar+",scrollbars="+scrollbars+",resizable="+resizable+",top='+((screen.height/2)-("+h/2+"))+',left='+((screen.width/2)-("+w/2+"))+'"+"')}else{myWin.focus();};void(0);");
};
And everything works perfectly. Note: Remove space between “java” and “script” (no quotes), the board automatically does that.