How to close current tab in chrome extension?

Question

I am new to chrome extensions, and I am trying to create a simple extension that closes the current tab if the element class matches.

This is my code in the content of the script:

$(document).ready(function() { if ($(".watchdogedit").length > 0) { setTimeout(CLOSECURRENTAB,3000); } }); 

I need a CLOSECCURENTTAB function.

Help me!

EDIT:

DONE!

content script:

 $(document).ready(function(){ if ($(".watchdogedit").length > 0) { setTimeout(closeTab, 3000); } }); function closeTab() { chrome.runtime.sendMessage({type: "closeTab"}); } 

background script:

 chrome.runtime.onMessage.addListener( function(request, sender, sendResponse) { if (request.type == "closeTab") { chrome.tabs.remove(sender.tab.id); } } );