How to avoid IE errors caused by debugging code

if(!){
var names = ["log", "debug", "info", "warn", "error", "assert", "dir", "dirxml","group", "groupEnd", "time", "timeEnd", "count", "trace", "profile", "profileEnd"];

= {};
for (var i = 0; i < ; i++){
[names[i]] = function() {};
}
}