Login control with RadioBox control

[Guest]

Hello All
I want to add RadioBox control or DropDownList control to my login page, so
the user can choose which database they want to use, but after I added
RadioBox control, It shows me the name" xxx" does not exist in the current
context.
below is code
protected void Login_Authenticate(object ..., Auth....)
{
string whichConnection;
if( RadioBox1.Checked =="DB1") <-------- no RadioBox1
whichConnection ==predefined connection 1
.....

}

or do I need to make customizing Login control myself

any help will really appricated!!!