Access contentscript from background.js
===

I have a context script injected to a website to change some of the HTML code in there.
(Just change **Pies** into **Cakes**
Now I want to do this only if I click on the extensions icon.

My manifest.json:

    {
    	"name": "helper",
    	"version": "1",
    	"description": "just a test",
    	"background": {
    		"scripts": ["background.js"]
    	},
    	"permissions": [ "tabs", "http://*/*" ],
    	"content_scripts": [ {
    		"all_frames": true,
    		"js": ["jquery.min.js",  "content.js", "changetext.js" ],
    		"matches": [ "http://*/*", "https://*/*" ] ,
    		"run_at": "document_end"
    	} ],
    	"icons": {	"48": "icon48.png",
    		"128": "icon128.png" },
    	"browser_action": {
    		"default_title": "BingoBlitz Helper",
    		"default_icon": "logo.png"
    	}
    }

My background.js:

       chrome.browserAction.onClicked.addListener(function(tab) {
        		alert('CLICK DETECTED');
                    chrome.tabs.executeScript(null, {file: 'changetext.js'});
         });

My changetext.js:

    alert ("Site Loaded");
    var txt = "<div id='container'>"+$('#container').html()+"</div>";
    var new_txt = txt.replace(/Pies\./g,"Cakes");


Now when I open a page (e.g. goole.com) I get the alert from changetext.js.
If I click on the extension icon, I get the alert from background.js

Just the background.js doe not start the changetext.js.


ANY HELP pls.