js获取验证码60s倒计时

<input id="getCodeId" type="button" number="60" value="获取验证码"></input>

$("#getCodeId").click(function(){
    var node = $(this);
	    $.ajax({
	        url:,
	        type:,
	        data:{
	        },
	        dataType:"json",
	        success:function(data){
	            send(node);
	        }
	    });
});

function send(obj) {
    var wtime = Number($(obj).attr('number'));
    if (wtime==0) {
        $(obj).attr('disabled', false);
        $(obj).css({'backgroundColor':'#d43b33','color':'#FFF'});
        $(obj).val('重新获取');
        $(obj).attr('number',60);
    }else{
        $(obj).attr('disabled', true);
        $(obj).css({'backgroundColor':'#E8E8E8','color':'#666'});
        wtime--;
        $(obj).attr('number',wtime);
        $(obj).val(wtime + '秒后重新获取');
        setTimeout(function () {
            send(obj);
        }, 1000);
    }
}