RadioButtonList SelectedValue

[thinkmast]

Hello All:

i am writing a .NET survey application using C#. There are a series of questions on the webpage with a radiobuttonlist for each question.

I am now trying to get the values from the database already to display on the radiobuttonlist..i was successful so far by using the code
rbl_name.SelectedValue=Convert.ToString(sql_select.Parameters["@rbl_name"].Value)

BUT, if the value in the database is NULL, it is giving an error.

I want NO radiobutton to be selected IF the value is NULL in the database.

Thanks,
Vijay