Passing DDL value to bit field in SQL

I have a DDL with two values: 0 and 1. When I use

sqlcommand.Parameters.Add(New SqlParameter("@.fld", SqlDbType.Bit, 1))
sqlcommandl.Parameters("@.fld").Value = System.Boolean.Parse(DropDownList1.SelectedValue)

or

sqlcommand.Parameters.Add(New SqlParameter("@.fld", SqlDbType.Bit, 1))
sqlcommandl.Parameters("@.fld").Value = System.Convert.ToBoolean(DropDownList1.SelectedValue)

to insert the selected value in a sql2k database BIT field I am given this error:

System.FormatException: String was not recognized as a valid Boolean.

How can I solve this problem?

// C# but you should get the idea
bool trueFalse = false;
if( DropDownList1.SelectedValue.Value.Equals("1") ){
 trueFalse = true;
}
sqlcommandl.Parameters("@.fld").Value = trueFalse;