consider table1 with 2 columns.. table1: column1 int, column2 char

create procedure SP1(@col1,@col2) as begin select * from table1 where _ end

Question: User may enter valid input for either (col1 or col2) or (both col1 and col2).so i need to validate the user input and use those correct column(s) in the satic query.

eg: if both inputs are correct then, the query will be. select * from table1 where column1=@col1 and column2 =@col2 if only col2 is valid and col1 is not a valida one, then select * from table1 where column2=@col2

how to validate the input parameters before using in the static query?? in sql server 2005