replace your frameset tags with these,
<frameset class="center" rows="100,*" frameborder="0" border="0" framespacing="0">
<frameset class="center" cols="200,*" frameborder="0" border="0" framespacing="0">
Addthese css codes for the page
.center
{
margin-left:auto;
margin-right:auto;
width:70%;
}