Thx. But why is there a checkboxgroup configuration in DataAssist Pages when it can't be used to enter data into the database? Or do I miss here something? That's confusing. 
Well, a checkbox group can be used to enter data to the database. A checkbox group is basically the same idea as a multiple select list. It allows the user to choose multiple options and store the values into a column of your database table
Is a checkbox group the right way to go for this problem at all? i don't know. What exactly is it you are trying to accomplish?
