I have a table like following. When I add link to each picture, the first element will have a red rectangle around it. What's the problem ?

<table>
<td><a href="./product.html"><img src = "./img/product.gif"></a></td>
<td><a href="./news.html" onMouseOver = "replaceImg('newsoff','newsover')" onMouseOut = "replaceImg('newsoff','newsoff')" ><img src = "./img/news.gif" name ="newsoff" ></a></td>
<td><a href="./recruit.html" onMouseOver = "replaceImg('recruitoff','recruitover')" onMouseOut = "replaceImg('recruitoff','recruitoff')" ><img src = "./img/recruit.gif" name ="recruitoff" ></a></td>
<td><a href="./contact.html" onMouseOver = "replaceImg('contactoff','contactover')" onMouseOut = "replaceImg('contactoff','contactoff')" ><img src = "./img/news.gif" name ="contactoff" ></a></td>
</table>