Execute script after click in popup.html (chrome extension)

I am trying to execute javascript on a page when I click on a button in popup.html. I tried to use such a way:

In background.js:

chrome.tabs.onUpdated.addListener(function(tabId, changeInfo){
    if(changeInfo.status == "loading") {
        insert(tabId);
    }
});
function insert(tabId) {
    chrome.tabs.get(tabId, function(tab) {
        $('button').click(function() {
            chrome.tabs.executeScript(tab.id, {file: 'js/alert.js'});
        });
    });
}

Alert.js consists only of one string: alert('works');

Alert is just an example. Real script should do some DOM manipulation with opened tab after user clicks on a button im popup.html.