Index: TODO
==================================================================
--- TODO
+++ TODO
@@ -35,6 +35,7 @@
 * Command-line switch for batch import/export levels
 * SQL
   * Implement the GROUP column in the CLASSES table
   * Allow multiple SQL statements in one binding
 * Large fonts (width 8 or 16, height 8-32)
+* Remember solved levels (store solved version in USERSTATE column)
 

Index: default.heromeshrc
==================================================================
--- default.heromeshrc
+++ default.heromeshrc
@@ -162,11 +162,11 @@
 ?.editClick.ctrl.left: select 'em',id from objects where x=$X and y=$Y and up is null;
 ?.editClick.alt.left: ^u
 ?.editClick.right: delete from objects where x=$X and y=$Y and up is null;
 
 ! Global key bindings
-?.?.kp_minus: select 'go',-(level()-1);
-?.?.kp_plus: select 'go',-(level()+1);
+?.?.kp_minus: select 'go',-(level()-1) where level()>1;
+?.?.kp_plus: select 'go',-(level()+1) where level()<max_level();
 ?.?.ctrl.G: select 'go',-:Go_To_Level where :Go_To_Level=cast(:Go_To_Level as int) and cast(:Go_To_Level as int)>0;
 ?.?.shift.ctrl.M: select ':s';
 ?.?.f10: select ':x';
 

Index: function.c
==================================================================
--- function.c
+++ function.c
@@ -258,10 +258,14 @@
   }
   if(sqlite3_value_type(*argv)==SQLITE_NULL) return;
   s=load_level(sqlite3_value_int(*argv));
   if(s) sqlite3_result_error(cxt,s,-1);
 }
+
+static void fn_max_level(sqlite3_context*cxt,int argc,sqlite3_value**argv) {
+  sqlite3_result_int(cxt,level_nindex);
+}
 
 static void fn_modstate(sqlite3_context*cxt,int argc,sqlite3_value**argv) {
   sqlite3_result_int(cxt,SDL_GetModState());
 }
 
@@ -974,10 +978,11 @@
   sqlite3_create_function(userdb,"LEVEL",0,SQLITE_UTF8,&level_ord,fn_level,0,0);
   sqlite3_create_function(userdb,"LEVEL_CACHEID",0,SQLITE_UTF8|SQLITE_DETERMINISTIC,ptr0,fn_cacheid,0,0);
   sqlite3_create_function(userdb,"LEVEL_ID",0,SQLITE_UTF8,&level_id,fn_level,0,0);
   sqlite3_create_function(userdb,"LEVEL_TITLE",0,SQLITE_UTF8,0,fn_level_title,0,0);
   sqlite3_create_function(userdb,"LOAD_LEVEL",1,SQLITE_UTF8,0,fn_load_level,0,0);
+  sqlite3_create_function(userdb,"MAX_LEVEL",0,SQLITE_UTF8,0,fn_max_level,0,0);
   sqlite3_create_function(userdb,"MODSTATE",0,SQLITE_UTF8,0,fn_modstate,0,0);
   sqlite3_create_function(userdb,"MOVE_LIST",0,SQLITE_UTF8,0,fn_move_list,0,0);
   sqlite3_create_function(userdb,"MOVENUMBER",0,SQLITE_UTF8,0,fn_movenumber,0,0);
   sqlite3_create_function(userdb,"MVALUE",1,SQLITE_UTF8|SQLITE_DETERMINISTIC,0,fn_mvalue,0,0);
   sqlite3_create_function(userdb,"NVALUE",1,SQLITE_UTF8|SQLITE_DETERMINISTIC,0,fn_zero_extend,0,0);

Index: sql.doc
==================================================================
--- sql.doc
+++ sql.doc
@@ -59,11 +59,11 @@
 
 LEVEL()
   The one-based order number of the current level.
 
 LEVEL_CACHEID()
-  The cache ID number of this level in the user cache table.
+  The user cache ID of the level file.
 
 LEVEL_ID()
   The ID number of the current level.
 
 LEVEL_TITLE()
@@ -103,10 +103,13 @@
   manager. Returns null if there is no such resource value.
 
 SIGN_EXTEND(number)
   Sign extends a 32-bit number to 64-bits.
 
+SOLUTION_CACHEID()
+  The user cache ID of the level file.
+
 TRACE_OFF()
   Disables tracing when called.
 
 TRACE_ON()
   Enables tracing when called.