rem: btn.addListener("click",onclick); 
add: if(onclick!=null) btn.addListener("click",onclick); 
context: function makeButton(e,onclick) {    var clsName = e.className;    var btn = new YAHOO.widget.Button(e,{});    btn.addListener("click",onclick);    Element.addClassName(btn.get("element"),clsName);}
meta: 3881	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/3881/1a0127eb6f5cef7781d49647a5562e17d94a6875/hudson-behavior.js/buggy/war/resources/scripts/hudson-behavior.js