ASP.NET

tag .The response which Iam getting from the database is in the form os HTML string.(on selection of a dropdown) something like:

<asp:textbox id="" .......="" xmlns:asp="#unknown">
uc:codelook id="" addedproperty="123" .....=""
<asp:label ....="" xmlns:asp="#unknown"> etc etc ....


Now Earlier I had been using
--->control xyz = ParseControl(HTMLString)
--->page.findcontrol("dIV_Tag") to get the specified div where the controls have to be added in an object objDIV.
---> and finally objDIV.addControl(control);

Now the problem comes in case of uc: tag which is a ascx user control .earlier uc tag was coming undefined for which i had add the namespace like <@register .....> to the the HTMLString due to which that prob was resolved but now the next problem which is coming is of the child controls which are being used under the ascx.

cause under the setter property inside the codebehind of ascx it was like :
public string AddedProperty
{
tt1.Attributes.Add("addedProperty", value );
}

tt1 is coming as undefined which is a child control --a textbox inside that usercontrol.even tried to set the child property from ascx thru inline coding by making a getter of the same property at code behind .
but again the value of addedProperty= "123" is not being set for child control.
What should be done ?Please suggest something as its urgent.