how can hide query string url?

Question

I use a repeater control and link to other page of their id but id are  dispaly , how can prevent
only display  page name
<asp:Repeater Runat="server" ID="reentrance" >
<ItemTemplate>
 <table width="100%" cellpadding="0" cellspacing="0" class="padding">
     <tr><td>
<a href="entrance_details.aspx?eid=<%#DataBinder.Eval(Container.DataItem,"exam_id")%>"class="inde">
                                                                                            <%#DataBinder.Eval(Container.DataItem,"Exam_name")%>
 </a>
</td>
</tr>
</table>
</ItemTemplate>

<asp:Repeater>


Url to display http://localhost:6329/Project/collegedetails.aspx?colid=2
 I want to display http://localhost:6329/Project/collegedetails.aspx

If it is posible ,plz quicklly help me