The problem you get from line 16 is because "InvFull" is a function in the SRL-Include, not SCAR. You have to include SRL like this:
SCAR Code:
Program Whatever_Your_Script_Is_Called;
{.include SRL/SRL.scar}
I fixed your whole script up, and I've added comments here and there pointing to some notes I have made further down this post:
SCAR Code:
program MineMiner;
{.include SRL/SRL.scar}
const
IronOre =1844540;
var
x, y: Integer;
procedure StartMining;
begin
if (FindColor(x,y,1844540,0,0,360,360)) then
begin
// Next 3 lines = Note #1
MoveMouseSmoothEx(x,y+random(0),20,40,45,25,20);
Wait(1000+random(100));
ClickMouse(x,y,false);
{To here}
begin
repeat { This line and the one below = Note #2 }
until(InvFull);
end;
end;
end;
procedure Dropping;
begin
if (InvFull) then
DropTo(2,28); // This line = Note #3
end;
function FindFastRandoms: Boolean; // By WT-Fakawi.
// This whole procedure = Note #4
var
i: Integer;
begin
for i:=1 to 10 do
begin
case I of
1: If FindDead then
begin
Result := True;
Loc('Dead');
Logout;
end;
2: If FindTalk Then Result := True;
3: If FindMime then
begin
Result := True;
Loc('Mime');
Logout;
end;
4: If FindMaze then
begin
result:= true;
Loc('Maze');
logout;
end;
5: If FindQuiz then
begin
Result := True;
Loc('Quiz');
Logout;//Solve quiz in next SRL
end;
6: If FindDemon then
begin
Result := True;
Loc('Demon');
end;
7: begin
if NoGameTab then
begin
Result := True;
Players[CurrentPlayer].rand := 'No GameTab';
Logout;
Exit;
end;
end;
8: begin
If InBlack then
begin
Result := True;
Players[CurrentPlayer].rand := 'InBlack';
Logout;
Exit;
end;
end;
9 : If FindTalk Then Result := True;
10: if FindFight then
begin
RunTo(RunDir, false);
FTWait(RunWaitTime);
RunBack;
end;
end;
Wait(1);
end;
end;
begin // From here and to "end." = Note #5
StartMining;
Dropping;
end.
Note #1: Those 3 lines can be replaced with a much safer and better procedure from SRL. It's called "Mouse" and will move you mouse to the specified location and click there.
will move and click the mouse on the coordinates 100,100 with 5 pixels randomness on both the x- and the y-axis.
Note #2: Here you have a loop that will not work. You set the script to click one color and then do nothing until your inventory is full. You have to incorporate the whole color-clicking part into the loop. Like this:
SCAR Code:
procedure StartMining;
begin
repeat
if (FindColor(x,y,1844540,0,0,360,360)) then
begin
Mouse(x,y,0,0,true) // I told you about this procedure before.
end;
until(InvFull); // I actually recommend using "InvCount=28" instead.
end;
Note #3: The procedure you are looking to use is "DropToPosition". A simple typo by you.
Note #4: That whole procedure ("FindFastRandoms") can be replaced with "FindNormalRandoms" from SRL.
Note #5: You must ALWAYS have a "main-loop" in a script. A mainloop begins with "begin" and ends (as the only thing at all!) with "end."
I would be a good idea to read more about main-loops. I strongly believe there is a Main-loop-tutorial in the "Tutorial Island" section.
If you have read and followed these notes, the script should compile. It might not work as you intend it to, but it will compile which is a good thing 
Enjoy, and good luck!
-Knives