Using an alert in the Firefox add-on builder -

i'm trying write first firefox extension using ff add-on builder. don't understand why seems code isn't running @ neither alert pops up. why doesn't alert("main"); create popup?

main.js

alert("main"); var data = require("sdk/self").data; var pagemod = require("sdk/page-mod"); pagemod.pagemod({   include: "*",   contentscriptfile: data.url("noredirectlinks.js"),   contentscriptwhen: "ready" }); 

noredirectlinks.js

alert("content script"); var alllinks = document.getelementsbytagname("a");     (var i=0, il=alllinks.length; i<il; i++) {     elm = alllinks[i];     if (elm.getattribute("onclick")) {         elm.onclick = null;     }     if (elm.getattribute("onmousedown")) {         elm.onmousedown = null;     } } 

the alert in main.js cannot show in browser. main addon code has not access browser page. access content, have use content scripts (as second script).

the alert in noredirectlinks.js should work. first test again without alert in main.js. must sure file located in data folder. case?

there error in code didn't provide explain why addon not executed. there other code or everything?