my nivo slider in wordpress dont showing arrows and navigation bar

hi after integrating the nivo slider in my wordpress the images are sliding perfectly with given animation. but the arrow images for prev and next is not showing.instead it shows

prev and next

in the slider. also instead of navigation bullets it shows numbers as 1234 , that navigate according to the images. in which file should i change to solve the problem?

the nivoslider.css is

.nivoSlider {
position:relative;
width:100%;
height:auto;
overflow: hidden;
}
 .nivoSlider img {
position:absolute;
top:0px;
left:0px;
max-width: none;
}
 .nivo-main-image {
display: block !important;
position: relative !important; 
width: 100% !important;
 }

  /* If an image is wrapped in a link */
   .nivoSlider a.nivo-imageLink {
position:absolute;
top:0px;
left:0px;
width:100%;
height:100%;
border:0;
padding:0;
margin:0;
z-index:6;
display:none;
background:white; 
filter:alpha(opacity=0); 
opacity:0;
   }
  /* The slices and boxes in the Slider */
   .nivo-slice {
display:block;
position:absolute;
z-index:5;
height:100%;
top:0;
    }
    .nivo-box {
display:block;
position:absolute;
z-index:5;
overflow:hidden;
    }
    .nivo-box img { display:block; }

     /* Caption styles */
     .nivo-caption {
position:absolute;
left:0px;
bottom:0px;
background:#000;
color:#fff;
width:100%;
z-index:8;
padding: 5px 10px;
opacity: 0.8;
overflow: hidden;
display: none;
-moz-opacity: 0.8;
filter:alpha(opacity=8);
-webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */
-moz-box-sizing: border-box;    /* Firefox, other Gecko */
box-sizing: border-box;         /* Opera/IE 8+ */
        }
     .nivo-caption p {
padding:5px;
margin:0;
       }
      .nivo-caption a {
display:inline !important;
        }
       .nivo-html-caption {
         display:none;
        }
        /* Direction nav styles (e.g. Next & Prev) */
      .nivo-directionNav a {
position:absolute;
top:45%;
z-index:9;
cursor:pointer;
       }
     .nivo-prevNav {
left:0px;
        }
       .nivo-nextNav {
right:0px;
       }
    /* Control nav styles (e.g. 1,2,3...) */
     .nivo-controlNav {
text-align:center;
padding: 15px 0;
    }
      .nivo-controlNav a {
cursor:pointer;
    }
   .nivo-controlNav a.active {
font-weight:bold;
     }

EDIT::

i found out the problem. its my mistake. sorry to all. i forgot to give get_template_directory_uri() in href.when i gave that arrows and bullets works perfectly. this question is resolved.