procedure DeleteElement(anArray:TStringArray;const aPosition:integer);
var
   lg, j : integer;
begin
   lg := length(anArray);
   if Length(anArray) < aPosition then
   exit;
   if aPosition = lg-1 then
     exit
   else if aPosition = lg-1 then begin //if is the last element
           //if TSomeType is a TObject descendant don't forget to free it
           //for example anArray[aPosition].free;
           Setlength(anArray, lg -1);
           exit;
        end;
   for j := aPosition to lg-2 do//we move all elements from aPosition+1 left...
     anArray[j] := anArray[j+1];//...with a position
   SetLength(anArray, lg-1);//now we have one element less
   //that's all...
end;