Edit in JSFiddle

Result
HTML
JavaScript
CSS

<html>
    <head><title>moving objects using animate</title></head>
<body>
    <div id="box">
    </div><br />
    <br />
    <button id="left"><<</button>
    <button id="right">>></button>
</body>
</html>

$(document).ready(function()
                  {
                      $("#left").click(function()
                                       {
                                           $("#box").animate({
                                               "marginLeft":"-=40px"
                                           },"slow");
                                       });
                      $("#right").click(function()
                                       {
                                           $("#box").animate({
                                               "marginLeft":"+=40px"
                                           },"slow");
                                       });
                      
                  });

#box
{
    background-color:Orange;
    height:100px;
    width:100px;
    margin-left:40px;
    margin-top:40px;
}