hi Mick2011,
When you select the cell with the formula it will highligh with boarder.
in the bottom right coener will be a small square.
click on hold and drag the forula down
Note if you dont want some of the cell references to change, first put a $ in from of the row or column value
eg =IF(AND(C6>=J$12,C6<$J$13),$K$12*C7,IF.......

c6 will change $j$13 wont