Performing post through Chrome extension, where does it go?

I want the below code to execute when I push the button I have added to my chrome browser through my开发者_如何学C extension:

    <script>
var formData = new FormData();  
var html = document.innerHTML;
formData.append("time", "12:00:00");  
formData.append("html",document.getElementsByTagName('html')[0].innerHTML);  

var xhr = new XMLHttpRequest();  
xhr.open("POST", "https://www.mywebsite.com/index");  
xhr.send(formData); 
</script>

my issues is I have no idea where does this go? background html? manifest? I cant understand how it works even after reading the document about the architecture can anyone help me?.

---

This code should go into background page. In order for it to work you need to add https://www.mywebsite.com to domain permissions first. It is all explained here with examples.

To catch browser action button click:

//background.html
chrome.browserAction.onClicked.addListener(function(tab) {
    var formData = new FormData();  
    ...
});

This will work only if you don't have a popup defined.