更新值-正负

I'd like to create a simple rater with php/ajax, which:

1) after clicking on plus refreshes the number of "thumbs up" +1
2) after clicking on minus refreshes the number of "thumbs down" -1
3) in both cases sends a mysql query to update the table - and it all should be without refreshing a page.

As I'm not really good at ajax stuff, I ask you for help. How to do that? I thought about load() function, but there would be loads of comments to rate, so writing each of them load() function will be really uncool. Please, provide me with some ideas, if possible with the examples. I count on you!

Paweł

PS This might be done with jquery, I dont mind.

As for now, I've tried to make adding numbers itself possible. But it is not working. Here is my html:

<a rel='tooltip' href='#ocentemat' title='Zgadzam się!' class='addplus'><i class='fa fa-thumbs-up'></i></a> <span class='plusy'>1</span>

and my scripting:

jQuery(document).ready(function($) {
    $(\".addplus\").click(function() {
     var currentValue = parseInt($(\"span.plusy\").text(),1);
 $('span.plusy').text(currentValue);
    });
});