--- a/src/lang/english.txt	Sun Nov 16 13:49:57 2008 +0000
+++ b/src/lang/english.txt	Sun Nov 16 14:17:49 2008 +0000
@@ -1643,6 +1643,7 @@
 STR_0807_ESTIMATED_INCOME                                       :{WHITE}Estimated Income: {CURRENCY}
 STR_0808_CAN_T_RAISE_LAND_HERE                                  :{WHITE}Can't raise land here...
 STR_0809_CAN_T_LOWER_LAND_HERE                                  :{WHITE}Can't lower land here...
+STR_CAN_T_LEVEL_LAND_HERE                                       :{WHITE}Can't level land here...
 STR_080A_ROCKS                                                  :Rocks
 STR_080B_ROUGH_LAND                                             :Rough land
 STR_080C_BARE_LAND                                              :Bare land
@@ -1655,8 +1656,9 @@
 STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION                         :{WHITE}Land sloped in wrong direction
 STR_1001_IMPOSSIBLE_TRACK_COMBINATION                           :{WHITE}Impossible track combination
 STR_1002_EXCAVATION_WOULD_DAMAGE                                :{WHITE}Excavation would damage tunnel
-STR_1003_ALREADY_AT_SEA_LEVEL                                   :{WHITE}Already at sea-level
-STR_1004_TOO_HIGH                                               :{WHITE}Too high
+STR_1003_ALREADY_AT_SEA_LEVEL                                   :{WHITE}... already at sea level
+STR_1004_TOO_HIGH                                               :{WHITE}... too high
+STR_ALREADY_LEVELLED                                            :{WHITE}... already flat
 STR_1005_NO_SUITABLE_RAILROAD_TRACK                             :{WHITE}No suitable railway track
 STR_1007_ALREADY_BUILT                                          :{WHITE}...already built
 STR_1008_MUST_REMOVE_RAILROAD_TRACK                             :{WHITE}Must remove railway track first

--- a/src/terraform_cmd.cpp	Sun Nov 16 13:49:57 2008 +0000
+++ b/src/terraform_cmd.cpp	Sun Nov 16 14:17:49 2008 +0000
@@ -359,6 +359,7 @@
 
 	/* Check range of destination height */
 	if (h > MAX_TILE_HEIGHT) return_cmd_error((oldh == 0) ? STR_1003_ALREADY_AT_SEA_LEVEL : STR_1004_TOO_HIGH);
+	if (p2 == 0) _error_message = STR_ALREADY_LEVELLED;
 
 	/* make sure sx,sy are smaller than ex,ey */
 	int ex = TileX(tile);

--- a/src/terraform_gui.cpp	Sun Nov 16 13:49:57 2008 +0000
+++ b/src/terraform_gui.cpp	Sun Nov 16 14:17:49 2008 +0000
@@ -123,7 +123,7 @@
 			DoCommandP(end_tile, start_tile, (uint32)-1, CcTerraform, CMD_LEVEL_LAND | CMD_MSG(STR_0809_CAN_T_LOWER_LAND_HERE));
 			break;
 		case DDSP_LEVEL_AREA:
-			DoCommandP(end_tile, start_tile, 0, CcPlaySound10, CMD_LEVEL_LAND);
+			DoCommandP(end_tile, start_tile, 0, CcPlaySound10, CMD_LEVEL_LAND | CMD_MSG(STR_CAN_T_LEVEL_LAND_HERE));
 			break;
 		case DDSP_CREATE_ROCKS:
 			GenerateRockyArea(end_tile, start_tile);