Disable and Enable submit button in jquery

I am using jquery to disable the submit button and load loading image,

In submit button I am using the folowing :

<div id="registerbtn" name="registerbtn">
<input type="submit" class="btn btn-primary" icon="ok white" value="Register" id="register" name="register"/>
</div>
<div class="span4" style="display:none;" id="loadingtext">
                            <?php echo  $imghtml=CHtml::image('images/loading.gif');?>                      
                        </div>

and in JQuery, I am using following code :

$(document).ready(function() {

    $('#register').click(function() {
        $('input[type="submit"]').attr('disabled','disabled');

     });
        $("#loadingtext").show();
    });
});

When I do this, then this button is disabled permanently, but if I want to remove then what should I do ??