problem with radio button list (checked)

Well I have problem with radio button check, which the data checked or not, get from sql server database,

name codes
mr. a 1
mr. b 3

codes = 1 (checked)
codes = 3 (checked)


and then put in;

Record 1:
<input id="Radio1" type="radio" value="1" name="rhn" runat="server" checked/>
<input id="Radio2" type="radio" value="2" name="rhn" runat="server" />
<input id="Radio3" type="radio" value="3" name="rhn" runat="server" />

Record 2:
<input id="Radio1" type="radio" value="1" name="rhn" runat="server" />
<input id="Radio2" type="radio" value="2" name="rhn" runat="server" />
<input id="Radio3" type="radio" value="3" name="rhn" runat="server" checked/>

i dont know how to put indicator code checked in asp.net.
anyone can help me??