I have one Parameter table and another data (transaction) table
When I fetch the data from data table I have put a when condition to one of date field in data table with between sy-datum and sy-datum + need to run days in parameter table
Its working properly
So my requirement is . 
There are three key fields (fixed) and
when the parameter value = 4 ALV columns must be 7
when the parameter value = 6 ALV columns must be 9
So I want to know how can I do this?
My second question is when the ALV displaying, user need to change there value in ALV list, so therefore ALV should be editable.
Please help me o solve these problems.