Two SQL Dialogs

Hi ,
We have created an Installscript MSI project , in that we have one SQl connection which has few SQL scripts in it. From OnSQLLogin function we are calling SQLServerSelectLogin dialog.
Now we had a new task to Show two SQL Dialogs in some cases only , according to one Property(or can be a string) value we need to show the second SQL dialog otherwise no need to show the second SQL dialog.

Can anybody help us how to work on two SQL Dialogs ?

Thanks in advance.