javascript - How can I perform an add function using jQuery -

i'm new javascript , need perform function! scenario is, there 2 elements used increase , decrease numerical value. value shown in element. i've shown image elements are! how can using javascript?

update :

i wrote following jquery function element click event. result doesn't change when click element.

 jquery(document).ready(function(){         jquery(".amount-increase").click(function(             var amount = parseint($(".bill-item-amount span")text(),10);             amount = amount + 1;             $(".bill-item-amount span").text(amount);         ));     }); 

here html element map.

 <div class="bill-item-description">  <!-- section item description , pricing -->  <div class="bill-item-name">  <p class="bill-item-name-left">normal cofee</p><p class="bill-item-name-right">170.00</p>  <div class="clear"></div>  </div>  <div class="bill-item-price">  <span>170.00 usd</span>  </div>  <div class="bill-item-amount">  <span>2</span>  </div>  </div>  <div class="bill-amount-selection">  <!-- section increment & decrement of item amount goes -->  <a class="amount-increase" href="#"></a>  <a class="amount-decrease" href="#"></a>  </div> 

http://jsfiddle.net/praveen16oct90/qkgzb/

take @ this.. created u...

              $(document).ready(function()         {         var x=2;                 $("#increase").click(function()                 {                          x+=1;                         $("#price").html(x);                  });          });