Update several cells based on entry

Hello again

pls take a look at these two sheets


how can I change the contents of one cell or a range of cells in a column based on
two cells ( here i.e. : ldate & Type) & update the found range of cells with a certain amount???

(all the cells in the column Amt will change if we have in sheet 1 the type A & date < 1/1/2003 - of course we have a link in the nb because we have 2 sheets)

Thank you