const
 n = ...;
type
 ar: array [1..n] of real;
 ...
 ...
function SearchM(mas: ar):real;
var
 i: integer; 
 max: real; 
 begin
  max:= mas[1];
  for i:= 1 to n do
   begin
    if mas[i] > max then
     max:= mas[i];
   end;
  SearchM:= max;
 end;