Very Simple Chrome Extension

I need a very simple Google Chrome extension (page_action or browser_action) that does the following: 1) the user tap on extension icon 2) content_script reads the source code of the page 3) content_script sends the content of the html <title> tag to popup 4) popup print the string in a <div> Keep in mind that: 1) If I click another browser tab, the string in popup should be updated immediately. 2) If the title tag is not available in page, a fallback string should be shown in popup.