diff --git a/lib/comp.c b/lib/comp.c
index e44dc75..91f76b4 100644
--- a/lib/comp.c
+++ b/lib/comp.c
@@ -659,7 +659,7 @@ static int emit_indexed_variable_access (hcl_t* hcl, hcl_oow_t index, hcl_oob_t
 	}
 
 	/* TODO: top-level... verify this. this will vary depending on how i implement the top-level and global variables... */
-	if (emit_single_param_instruction (hcl, baseinst2, index, srcloc) <= -1) return -1;
+	if (emit_single_param_instruction(hcl, baseinst2, index, srcloc) <= -1) return -1;
 	return 0;
 }
 
@@ -2012,7 +2012,7 @@ static HCL_INLINE int compile_catch (hcl_t* hcl)
 	hcl_cnode_t* cmd, * obj, * src, * exarg;
 	hcl_cframe_t* cf;
 	hcl_ooi_t jump_inst_pos;
-	hcl_oow_t exarg_offset;
+	hcl_oow_t exarg_offset, exarg_index;
 
 	cf = GET_TOP_CFRAME(hcl);
 	HCL_ASSERT (hcl, cf->opcode == COP_COMPILE_CATCH);
@@ -2053,9 +2053,10 @@ static HCL_INLINE int compile_catch (hcl_t* hcl)
 /* -------------------------------------------- */
 	/* add the exception variable to the local variable list... increase the number of local variables */
 	exarg_offset = hcl->c->tv.s.len + 1; /* when the variable name is added, its offset will be the current length + 1 for a space character added */
+	exarg_index = hcl->c->tv.wcount;
 	if (add_temporary_variable(hcl, HCL_CNODE_GET_TOK(exarg), hcl->c->tv.s.len) <= -1) return -1;
 	HCL_ASSERT (hcl, hcl->c->fnblk.info[hcl->c->fnblk.depth].tmprlen == hcl->c->tv.s.len - HCL_CNODE_GET_TOKLEN(exarg) - 1);
-	HCL_ASSERT (hcl, hcl->c->fnblk.info[hcl->c->fnblk.depth].tmprcnt == hcl->c->tv.wcount - 1);
+	HCL_ASSERT (hcl, hcl->c->fnblk.info[hcl->c->fnblk.depth].tmprcnt == exarg_index);
 	hcl->c->fnblk.info[hcl->c->fnblk.depth].tmprlen = hcl->c->tv.s.len;
 	hcl->c->fnblk.info[hcl->c->fnblk.depth].tmprcnt = hcl->c->tv.wcount;
 /* -------------------------------------------- */
@@ -2065,6 +2066,9 @@ static HCL_INLINE int compile_catch (hcl_t* hcl)
 	/* jump_inst_pos hold the instruction pointer that skips the catch block at the end of the try block */
 	patch_nearest_post_try (hcl, &jump_inst_pos); 
 
+	/* produce an instruction to store the exception value to an exception variable pushed by the 'throw' instruction */
+	if (emit_indexed_variable_access(hcl, exarg_index, HCL_CODE_POP_INTO_CTXTEMPVAR_0, HCL_CODE_POP_INTO_TEMPVAR_0, HCL_CNODE_GET_LOC(src)) <= -1) return -1;
+
 	SWITCH_TOP_CFRAME (hcl, COP_COMPILE_OBJECT_LIST, obj);
 
 	PUSH_SUBCFRAME (hcl, COP_POST_CATCH, cmd);
@@ -3682,6 +3686,7 @@ int hcl_compile (hcl_t* hcl, hcl_cnode_t* obj)
 {
 	hcl_oow_t saved_bc_len, saved_lit_len;
 	hcl_bitmask_t log_default_type_mask;
+	hcl_fnblk_info_t top_fnblk_saved;
 
 	HCL_ASSERT (hcl, GET_TOP_CFRAME_INDEX(hcl) < 0);
 
@@ -3691,15 +3696,6 @@ int hcl_compile (hcl_t* hcl, hcl_cnode_t* obj)
 	log_default_type_mask = hcl->log.default_type_mask;
 	hcl->log.default_type_mask |= HCL_LOG_COMPILER;
 
-	HCL_ASSERT (hcl, hcl->c->tv.s.len == 0);
-	HCL_ASSERT (hcl, hcl->c->tv.wcount == 0);
-	HCL_ASSERT (hcl, hcl->c->fnblk.depth == -1);
-	HCL_ASSERT (hcl, hcl->c->cblk.depth == -1);
-
-/* TODO: in case i implement all global variables as block arguments at the top level...what should i do? */
-
-	
-
 	/* 
 	 * In the non-INTERACTIVE mode, the literal frame base doesn't matter.
 	 * Only the initial function object contains the literal frame. 
@@ -3730,9 +3726,23 @@ int hcl_compile (hcl_t* hcl, hcl_cnode_t* obj)
 	 *  @0         (a)
 	 *  @1         (set-a) 
 	 */
+
+/* TODO: in case i implement all global variables as block arguments at the top level...what should i do? */
+	HCL_ASSERT (hcl, hcl->c->cblk.depth == -1);
+
+	if (hcl->c->fnblk.depth <= -1)
+	{
+		HCL_ASSERT (hcl, hcl->c->fnblk.depth == -1);
+		HCL_ASSERT (hcl, hcl->c->tv.s.len == 0);
+		HCL_ASSERT (hcl, hcl->c->tv.wcount == 0);
+
 /* TODO: HCL_TYPE_MAX(hcl_oow_t) as make_inst_pos is wrong for this top-level. fix it later ... 
  * finxing it is needed to support exception variable at the top-level... */
-	if (push_fnblk(hcl, HCL_NULL, hcl->c->tv.wcount, hcl->c->tv.s.len, HCL_TYPE_MAX(hcl_oow_t), 0) <= -1) return -1;
+		/* keep a virtual function block for the top-level compilation */
+		if (push_fnblk(hcl, HCL_NULL, hcl->c->tv.wcount, hcl->c->tv.s.len, HCL_TYPE_MAX(hcl_oow_t), 0) <= -1) return -1;
+	}
+	top_fnblk_saved = hcl->c->fnblk.info[0];
+	HCL_ASSERT (hcl, hcl->c->fnblk.depth == 0); /* ensure the virtual function block is added */
 
 	PUSH_CFRAME (hcl, COP_COMPILE_OBJECT, obj);
 
@@ -3911,11 +3921,13 @@ int hcl_compile (hcl_t* hcl, hcl_cnode_t* obj)
 	if (emit_byte_instruction(hcl, HCL_CODE_POP_STACKTOP, HCL_NULL) <= -1) goto oops;
 
 	HCL_ASSERT (hcl, GET_TOP_CFRAME_INDEX(hcl) < 0);
-	HCL_ASSERT (hcl, hcl->c->tv.s.len == 0);
-	HCL_ASSERT (hcl, hcl->c->tv.wcount == 0);
+	HCL_ASSERT (hcl, hcl->c->tv.s.len >= hcl->c->fnblk.info[0].tmprlen);
+	HCL_ASSERT (hcl, hcl->c->tv.wcount >= hcl->c->fnblk.info[0].tmprcnt);
 	HCL_ASSERT (hcl, hcl->c->cblk.depth == -1); /* no control blocks expected at this point */
-	HCL_ASSERT (hcl, hcl->c->fnblk.depth == 0);
-	pop_fnblk (hcl);
+
+	HCL_ASSERT (hcl, hcl->c->fnblk.depth == 0); /* ensure the virtual function block be the only one left */
+	hcl->code.ngtmprs = hcl->c->fnblk.info[0].tmprcnt; /* populate the number of global temporary variables */
+	/*pop_fnblk (hcl);  keep the top-level virtual function block by keeping this line commented out */
 
 	hcl ->log.default_type_mask = log_default_type_mask;
 	return 0;
@@ -3932,8 +3944,15 @@ oops:
 	/* quick way to call pop_cblk() and pop_fnblk() as many times as necessary */
 	hcl->c->tv.s.len = 0;
 	hcl->c->tv.wcount = 0;
-	hcl->c->fnblk.depth = -1;
 	hcl->c->cblk.depth = -1;
 
+	/*hcl->c->fnblk.depth = -1;*/
+	if (hcl->c->fnblk.depth > 0) 
+	{
+		hcl->c->fnblk.depth = 0;
+		hcl->c->fnblk.info[0] = top_fnblk_saved;
+	}
+	
+
 	return -1;
 }
diff --git a/lib/exec.c b/lib/exec.c
index 7f9b967..226a933 100644
--- a/lib/exec.c
+++ b/lib/exec.c
@@ -2075,37 +2075,6 @@ static HCL_INLINE int do_throw (hcl_t* hcl, hcl_oop_t val, hcl_ooi_t ip)
 	hcl_oop_context_t catch_ctx;
 	hcl_ooi_t catch_ip;
 
-#if 0
-	hcl_ooi_t flags;
-
-	ctx = hcl->active_context;
-	while ((hcl_oop_t)ctx != hcl->_nil)
-	{
-		flags = HCL_OOP_TO_SMOOI(ctx->flags);
-		if (flags &  1) /* TODO: use an enumerator instead of 1 */
-		{
-			return activate_block_for_throw_catch (hcl, (hcl_oop_block_t)ctx->slot[0], val, ctx->sender);
-/* TOOD: arrange to unwind.... */
-		}
-
-		ctx = ctx->sender;
-	}
-	
-	if (hcl->active_function->dbgi != hcl->_nil)
-	{
-		hcl_dbgi_t* dbgi;
-		dbgi = (hcl_dbgi_t*)HCL_OBJ_GET_BYTE_SLOT(hcl->active_function->dbgi);
-		HCL_LOG2 (hcl, HCL_LOG_IC | HCL_LOG_WARN, "exception not handled %js:%zu", (dbgi[ip].fname? dbgi[ip].fname: oocstr_dash), dbgi[ip].sline);
-	}
-	else
-	{
-		HCL_LOG0 (hcl, HCL_LOG_IC | HCL_LOG_WARN, "exception not handled");
-	}
-	
-	/* exception not handled. terminate the active process */
-	terminate_process (hcl, hcl->processor->active);
-	return 0;
-#else
 	if (HCL_EXSTACK_ISEMPTY(hcl))
 	{
 		if (hcl->active_function->dbgi != hcl->_nil)
@@ -2134,8 +2103,10 @@ static HCL_INLINE int do_throw (hcl_t* hcl, hcl_oop_t val, hcl_ooi_t ip)
 	hcl->ip = -1; /* mark context dead. saved into hcl->active_context->ip in SWITCH_ACTIVE_CONTEXT */
 	SWITCH_ACTIVE_CONTEXT (hcl, catch_ctx);
 	hcl->ip = catch_ip; /* override the instruction pointer */
+
+	/* push the exception value to the stack */
+	HCL_STACK_PUSH (hcl, val);
 	return 0;
-#endif
 }
 
 /* ------------------------------------------------------------------------- */
@@ -3270,7 +3241,7 @@ static int execute (hcl_t* hcl)
 				return_value = HCL_STACK_GETTOP(hcl);
 				HCL_STACK_POP (hcl);
 
-				if (do_throw (hcl, return_value, fetched_instruction_pointer) <= -1) goto oops;
+				if (do_throw(hcl, return_value, fetched_instruction_pointer) <= -1) goto oops;
 				break;
 			/* -------------------------------------------------------- */
 
@@ -3929,7 +3900,7 @@ hcl_oop_t hcl_execute (hcl_t* hcl)
 	if (HCL_UNLIKELY(!func)) return HCL_NULL;
 
 	/* pass nil for the home context of the initial function */
-	fill_function_data (hcl, func, 0, 0, (hcl_oop_context_t)hcl->_nil, hcl->code.lit.arr->slot, hcl->code.lit.len);
+	fill_function_data (hcl, func, 0, hcl->code.ngtmprs, (hcl_oop_context_t)hcl->_nil, hcl->code.lit.arr->slot, hcl->code.lit.len);
 
 	hcl->initial_function = func; /* the initial function is ready */
 
diff --git a/lib/hcl.h b/lib/hcl.h
index b3510b7..c6fea5e 100644
--- a/lib/hcl.h
+++ b/lib/hcl.h
@@ -1543,8 +1543,10 @@ struct hcl_t
 			hcl_oow_t len;
 		} lit;
 
-		/* array that hold the location of the byte code emitted */
+		/* the cumulative number of temporaries collected at the global(top-level) level */
+		hcl_oow_t ngtmprs; 
 
+		/* array that holds the location of the byte code emitted */
 		hcl_dbgi_t* dbgi;
 	} code;