diff --git a/asm/field_message_box.s b/asm/field_message_box.s
deleted file mode 100644
index 0c1fae6de..000000000
--- a/asm/field_message_box.s
+++ /dev/null
@@ -1,337 +0,0 @@
-	.include "asm/macros.inc"
-	.include "constants/constants.inc"
-
-	.syntax unified
-
-	.text
-
-	thumb_func_start sub_8098128
-sub_8098128: @ 8098128
-	ldr r1, =gUnknown_020375BC
-	movs r0, 0
-	strb r0, [r1]
-	ldr r2, =gTextFlags
-	ldrb r1, [r2]
-	movs r0, 0x2
-	negs r0, r0
-	ands r0, r1
-	movs r1, 0x3
-	negs r1, r1
-	ands r0, r1
-	subs r1, 0x2
-	ands r0, r1
-	subs r1, 0x4
-	ands r0, r1
-	strb r0, [r2]
-	bx lr
-	.pool
-	thumb_func_end sub_8098128
-
-	thumb_func_start sub_8098154
-sub_8098154: @ 8098154
-	push {r4,r5,lr}
-	lsls r0, 24
-	lsrs r5, r0, 24
-	lsls r0, r5, 2
-	adds r0, r5
-	lsls r0, 3
-	ldr r1, =gTasks
-	adds r4, r0, r1
-	movs r1, 0x8
-	ldrsh r0, [r4, r1]
-	cmp r0, 0x1
-	beq _08098188
-	cmp r0, 0x1
-	bgt _0809817C
-	cmp r0, 0
-	beq _08098182
-	b _080981B0
-	.pool
-_0809817C:
-	cmp r0, 0x2
-	beq _08098198
-	b _080981B0
-_08098182:
-	bl sub_81973A4
-	b _08098190
-_08098188:
-	movs r0, 0
-	movs r1, 0x1
-	bl sub_81973C4
-_08098190:
-	ldrh r0, [r4, 0x8]
-	adds r0, 0x1
-	strh r0, [r4, 0x8]
-	b _080981B0
-_08098198:
-	bl sub_8197224
-	lsls r0, 16
-	lsrs r0, 16
-	cmp r0, 0x1
-	beq _080981B0
-	ldr r1, =gUnknown_020375BC
-	movs r0, 0
-	strb r0, [r1]
-	adds r0, r5, 0
-	bl DestroyTask
-_080981B0:
-	pop {r4,r5}
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end sub_8098154
-
-	thumb_func_start task_add_textbox
-task_add_textbox: @ 80981BC
-	push {lr}
-	ldr r0, =sub_8098154
-	movs r1, 0x50
-	bl CreateTask
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end task_add_textbox
-
-	thumb_func_start task_del_textbox
-task_del_textbox: @ 80981D0
-	push {lr}
-	ldr r0, =sub_8098154
-	bl FindTaskIdByFunc
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0xFF
-	beq _080981E4
-	bl DestroyTask
-_080981E4:
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end task_del_textbox
-
-	thumb_func_start ShowFieldMessage
-ShowFieldMessage: @ 80981EC
-	push {r4,lr}
-	adds r1, r0, 0
-	ldr r4, =gUnknown_020375BC
-	ldrb r0, [r4]
-	cmp r0, 0
-	bne _0809820C
-	adds r0, r1, 0
-	movs r1, 0x1
-	bl textbox_fdecode_auto_and_task_add
-	movs r0, 0x2
-	strb r0, [r4]
-	movs r0, 0x1
-	b _0809820E
-	.pool
-_0809820C:
-	movs r0, 0
-_0809820E:
-	pop {r4}
-	pop {r1}
-	bx r1
-	thumb_func_end ShowFieldMessage
-
-	thumb_func_start sub_8098214
-sub_8098214: @ 8098214
-	push {r4,lr}
-	lsls r0, 24
-	lsrs r4, r0, 24
-	bl sub_8196094
-	adds r1, r0, 0
-	cmp r1, 0
-	bne _0809822E
-	ldr r0, =gUnknown_020375BC
-	strb r1, [r0]
-	adds r0, r4, 0
-	bl DestroyTask
-_0809822E:
-	pop {r4}
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end sub_8098214
-
-	thumb_func_start sub_8098238
-sub_8098238: @ 8098238
-	push {r4,r5,lr}
-	adds r4, r0, 0
-	ldr r5, =gUnknown_020375BC
-	ldrb r0, [r5]
-	cmp r0, 0
-	bne _08098270
-	ldr r0, =gStringVar4
-	adds r1, r4, 0
-	bl StringExpandPlaceholders
-	ldr r0, =sub_8098214
-	movs r1, 0
-	bl CreateTask
-	adds r0, r4, 0
-	bl sub_8196080
-	movs r0, 0x2
-	strb r0, [r5]
-	movs r0, 0x1
-	b _08098272
-	.pool
-_08098270:
-	movs r0, 0
-_08098272:
-	pop {r4,r5}
-	pop {r1}
-	bx r1
-	thumb_func_end sub_8098238
-
-	thumb_func_start ShowFieldAutoScrollMessage
-ShowFieldAutoScrollMessage: @ 8098278
-	push {lr}
-	adds r1, r0, 0
-	ldr r2, =gUnknown_020375BC
-	ldrb r0, [r2]
-	cmp r0, 0
-	bne _08098298
-	movs r0, 0x3
-	strb r0, [r2]
-	adds r0, r1, 0
-	movs r1, 0
-	bl textbox_fdecode_auto_and_task_add
-	movs r0, 0x1
-	b _0809829A
-	.pool
-_08098298:
-	movs r0, 0
-_0809829A:
-	pop {r1}
-	bx r1
-	thumb_func_end ShowFieldAutoScrollMessage
-
-	thumb_func_start sub_80982A0
-sub_80982A0: @ 80982A0
-	push {lr}
-	ldr r2, =gUnknown_020375BC
-	movs r1, 0x3
-	strb r1, [r2]
-	movs r1, 0x1
-	bl textbox_fdecode_auto_and_task_add
-	movs r0, 0x1
-	pop {r1}
-	bx r1
-	.pool
-	thumb_func_end sub_80982A0
-
-	thumb_func_start sub_80982B8
-sub_80982B8: @ 80982B8
-	push {lr}
-	ldr r1, =gUnknown_020375BC
-	ldrb r0, [r1]
-	cmp r0, 0
-	bne _080982D4
-	movs r0, 0x2
-	strb r0, [r1]
-	bl textbox_auto_and_task_add
-	movs r0, 0x1
-	b _080982D6
-	.pool
-_080982D4:
-	movs r0, 0
-_080982D6:
-	pop {r1}
-	bx r1
-	thumb_func_end sub_80982B8
-
-	thumb_func_start textbox_fdecode_auto_and_task_add
-textbox_fdecode_auto_and_task_add: @ 80982DC
-	push {r4,lr}
-	adds r2, r0, 0
-	adds r4, r1, 0
-	ldr r0, =gStringVar4
-	adds r1, r2, 0
-	bl StringExpandPlaceholders
-	lsls r4, 24
-	lsrs r4, 24
-	adds r0, r4, 0
-	bl AddTextPrinterForMessage
-	bl task_add_textbox
-	pop {r4}
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end textbox_fdecode_auto_and_task_add
-
-	thumb_func_start textbox_auto_and_task_add
-textbox_auto_and_task_add: @ 8098304
-	push {lr}
-	movs r0, 0x1
-	bl AddTextPrinterForMessage
-	bl task_add_textbox
-	pop {r0}
-	bx r0
-	thumb_func_end textbox_auto_and_task_add
-
-	thumb_func_start HideFieldMessageBox
-HideFieldMessageBox: @ 8098314
-	push {lr}
-	bl task_del_textbox
-	movs r0, 0
-	movs r1, 0x1
-	bl sub_8197434
-	ldr r1, =gUnknown_020375BC
-	movs r0, 0
-	strb r0, [r1]
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end HideFieldMessageBox
-
-	thumb_func_start textbox_any_visible
-textbox_any_visible: @ 8098330
-	ldr r0, =gUnknown_020375BC
-	ldrb r0, [r0]
-	bx lr
-	.pool
-	thumb_func_end textbox_any_visible
-
-	thumb_func_start IsFieldMessageBoxHidden
-IsFieldMessageBoxHidden: @ 809833C
-	push {lr}
-	ldr r0, =gUnknown_020375BC
-	ldrb r0, [r0]
-	cmp r0, 0
-	beq _08098350
-	movs r0, 0
-	b _08098352
-	.pool
-_08098350:
-	movs r0, 0x1
-_08098352:
-	pop {r1}
-	bx r1
-	thumb_func_end IsFieldMessageBoxHidden
-
-	thumb_func_start sub_8098358
-sub_8098358: @ 8098358
-	push {lr}
-	bl task_del_textbox
-	movs r0, 0
-	movs r1, 0x1
-	bl sub_81973FC
-	ldr r1, =gUnknown_020375BC
-	movs r0, 0
-	strb r0, [r1]
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end sub_8098358
-
-	thumb_func_start sub_8098374
-sub_8098374: @ 8098374
-	push {lr}
-	bl task_del_textbox
-	ldr r1, =gUnknown_020375BC
-	movs r0, 0
-	strb r0, [r1]
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end sub_8098374
-
-	.align 2, 0 @ Don't pad with nop.
diff --git a/ld_script.txt b/ld_script.txt
index f2a9d8196..44b503c55 100644
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -98,7 +98,7 @@ SECTIONS {
         src/field_map_obj.o(.text);
         asm/field_ground_effect.o(.text);
         asm/map_obj_8097404.o(.text);
-        asm/field_message_box.o(.text);
+        src/field_message_box.o(.text);
         asm/map_obj_lock.o(.text);
         src/text_window.o(.text);
         src/script.o(.text);
diff --git a/src/field_message_box.c b/src/field_message_box.c
new file mode 100755
index 000000000..fc51bc588
--- /dev/null
+++ b/src/field_message_box.c
@@ -0,0 +1,162 @@
+#include "global.h"
+#include "string.h"
+#include "string_util.h"
+#include "task.h"
+#include "text.h"
+
+extern void sub_81973A4(void);
+extern void sub_81973C4(u8, u8);
+extern u16 sub_8197224(void);
+extern int sub_8196094(void);
+extern void sub_8196080(u8*);
+extern void AddTextPrinterForMessage(u8);
+extern void sub_8197434(u8, u8);
+extern void sub_81973FC(u8, u8);
+
+extern u8 gUnknown_020375BC;
+
+void textbox_fdecode_auto_and_task_add(u8*, int);
+void textbox_auto_and_task_add(void);
+
+void sub_8098128(void)
+{
+    gUnknown_020375BC = 0;
+    gTextFlags.flag_0 = 0;
+    gTextFlags.flag_1 = 0;
+    gTextFlags.flag_2 = 0;
+    gTextFlags.flag_3 = 0;
+}
+
+void sub_8098154(u8 taskId)
+{
+    struct Task *task = &gTasks[taskId];
+    
+    switch (task->data[0])
+    {
+        case 0:
+           sub_81973A4();
+           task->data[0]++;
+           break;
+        case 1:
+           sub_81973C4(0, 1);
+           task->data[0]++;
+           break;
+        case 2:
+            if (sub_8197224() != 1)
+            {
+                gUnknown_020375BC = 0;
+                DestroyTask(taskId);
+            }
+    }
+}
+
+void task_add_textbox(void)
+{
+    CreateTask(sub_8098154, 0x50);
+}
+
+void task_del_textbox(void)
+{
+    u8 taskId = FindTaskIdByFunc(sub_8098154);
+    if (taskId != 0xFF)
+        DestroyTask(taskId);
+}
+
+bool8 ShowFieldMessage(u8 *str)
+{
+    if (gUnknown_020375BC != 0)
+        return FALSE;
+    textbox_fdecode_auto_and_task_add(str, 1);
+    gUnknown_020375BC = 2;
+    return TRUE; 
+}
+
+void sub_8098214(u8 taskId)
+{
+    if (sub_8196094() == 0)
+    {
+        gUnknown_020375BC = 0;
+        DestroyTask(taskId);
+    }
+}
+
+bool8 sub_8098238(u8 *str)
+{
+    if (gUnknown_020375BC != 0)
+        return FALSE;
+    StringExpandPlaceholders(gStringVar4, str);
+    CreateTask(sub_8098214, 0);
+    sub_8196080(str);
+    gUnknown_020375BC = 2;
+    return TRUE;
+}
+
+bool8 ShowFieldAutoScrollMessage(u8 *str)
+{
+    if (gUnknown_020375BC != 0)
+        return FALSE;
+    gUnknown_020375BC = 3;
+    textbox_fdecode_auto_and_task_add(str, 0);
+    return TRUE;
+}
+
+bool8 sub_80982A0(u8 *str)
+{
+    gUnknown_020375BC = 3;
+    textbox_fdecode_auto_and_task_add(str, 1);
+    return TRUE;
+}
+
+bool8 sub_80982B8(void)
+{
+    if (gUnknown_020375BC != 0)
+        return FALSE;
+    gUnknown_020375BC = 2;
+    textbox_auto_and_task_add();
+    return TRUE;
+}
+
+void textbox_fdecode_auto_and_task_add(u8* str, int a)
+{
+    StringExpandPlaceholders(gStringVar4, str);
+    AddTextPrinterForMessage(a);
+    task_add_textbox();
+}
+
+void textbox_auto_and_task_add(void)
+{
+    AddTextPrinterForMessage(1);
+    task_add_textbox();
+}
+
+void HideFieldMessageBox(void)
+{
+    task_del_textbox();
+    sub_8197434(0, 1);
+    gUnknown_020375BC = 0;
+}
+
+u8 textbox_any_visible(void)
+{
+    return gUnknown_020375BC;
+}
+
+bool8 IsFieldMessageBoxHidden(void)
+{
+    if (gUnknown_020375BC == 0)
+        return TRUE;
+    return FALSE;
+}
+
+void sub_8098358(void)
+{
+    task_del_textbox();
+    sub_81973FC(0, 1);
+    gUnknown_020375BC = 0;
+}
+
+void sub_8098374(void)
+{
+    task_del_textbox();
+    gUnknown_020375BC = 0;
+}