diff --git a/HISTORY b/HISTORY
old mode 100644
new mode 100755
index 9a859d6..bbc4522
--- a/HISTORY
+++ b/HISTORY
@@ -1,3 +1,7 @@
+Apr. 27 2015
+Added code line inserting/removing to interpreter shell
+Changed mb_dispose_value as public
+
 Apr. 23 2015 Version 1.1
 Added debug APIs
 Added (nestable) multi line IF statement support
diff --git a/MY-BASIC Quick Reference.pdf b/MY-BASIC Quick Reference.pdf
old mode 100644
new mode 100755
index fcaa239..214a089
Binary files a/MY-BASIC Quick Reference.pdf and b/MY-BASIC Quick Reference.pdf differ
diff --git a/README.md b/README.md
old mode 100644
new mode 100755
diff --git a/core/my_basic.c b/core/my_basic.c
old mode 100644
new mode 100755
index e342a76..f7a06ab
--- a/core/my_basic.c
+++ b/core/my_basic.c
@@ -77,7 +77,7 @@ extern "C" {
 /** Macros */
 #define _VER_MAJOR 1
 #define _VER_MINOR 1
-#define _VER_REVISION 51
+#define _VER_REVISION 52
 #define _MB_VERSION ((_VER_MAJOR * 0x01000000) + (_VER_MINOR * 0x00010000) + (_VER_REVISION))
 
 /* Uncomment this line to treat warnings as error */
@@ -686,15 +686,6 @@ static int _close_std_lib(mb_interpreter_t* s);
 
 /* ========================================================} */
 
-/*
-** {========================================================
-** Protected function declarations
-*/
-
-MBAPI int mb_dispose_value(mb_interpreter_t* s, mb_value_t val);
-
-/* ========================================================} */
-
 /*
 ** {========================================================
 ** Lib declarations
@@ -3138,25 +3129,6 @@ int _close_std_lib(mb_interpreter_t* s) {
 
 /* ========================================================} */
 
-/*
-** {========================================================
-** Protected function definitions
-*/
-
-int mb_dispose_value(mb_interpreter_t* s, mb_value_t val) {
-	/* Dispose a value */
-	int result = MB_FUNC_OK;
-
-	mb_assert(s);
-
-	if(val.type == MB_DT_STRING)
-		mb_free(val.value.string);
-
-	return result;
-}
-
-/* ========================================================} */
-
 /*
 ** {========================================================
 ** Public functions definitions
@@ -3751,6 +3723,18 @@ int mb_push_value(struct mb_interpreter_t* s, void** l, mb_value_t val) {
 	return result;
 }
 
+int mb_dispose_value(struct mb_interpreter_t* s, mb_value_t val) {
+	/* Dispose a value */
+	int result = MB_FUNC_OK;
+
+	mb_assert(s);
+
+	if(val.type == MB_DT_STRING)
+		mb_free(val.value.string);
+
+	return result;
+}
+
 int mb_load_string(struct mb_interpreter_t* s, const char* l) {
 	/* Load a script string */
 	int result = MB_FUNC_OK;
diff --git a/core/my_basic.h b/core/my_basic.h
old mode 100644
new mode 100755
index 77bae60..fc01e19
--- a/core/my_basic.h
+++ b/core/my_basic.h
@@ -247,6 +247,7 @@ MBAPI int mb_push_real(struct mb_interpreter_t* s, void** l, real_t val);
 MBAPI int mb_push_string(struct mb_interpreter_t* s, void** l, char* val);
 MBAPI int mb_push_usertype(struct mb_interpreter_t* s, void** l, void* val);
 MBAPI int mb_push_value(struct mb_interpreter_t* s, void** l, mb_value_t val);
+MBAPI int mb_dispose_value(struct mb_interpreter_t* s, mb_value_t val);
 
 MBAPI int mb_load_string(struct mb_interpreter_t* s, const char* l);
 MBAPI int mb_load_file(struct mb_interpreter_t* s, const char* f);
diff --git a/output/my_basic.exe b/output/my_basic.exe
old mode 100644
new mode 100755
index bce7c67..6081480
Binary files a/output/my_basic.exe and b/output/my_basic.exe differ
diff --git a/output/my_basic_mac b/output/my_basic_mac
index 8b5fca4..26693a4 100755
Binary files a/output/my_basic_mac and b/output/my_basic_mac differ
diff --git a/resource/my_basic.aps b/resource/my_basic.aps
old mode 100644
new mode 100755
diff --git a/resource/my_basic.rc b/resource/my_basic.rc
old mode 100644
new mode 100755
index 4a6b859..3111977
--- a/resource/my_basic.rc
+++ b/resource/my_basic.rc
@@ -36,8 +36,8 @@
 	IDI_ICON_MAIN ICON "icon.ico"
 
 	VS_VERSION_INFO VERSIONINFO
-	FILEVERSION 1,1,51,0
-	PRODUCTVERSION 1,1,51,0
+	FILEVERSION 1,1,52,0
+	PRODUCTVERSION 1,1,52,0
 	FILEFLAGSMASK 0x17L
 #	ifdef _DEBUG
 	FILEFLAGS 0x1L
@@ -55,13 +55,13 @@
 				VALUE "Comments", "MY-BASIC"
 				VALUE "CompanyName", "W. Renxin"
 				VALUE "FileDescription", "MY-BASIC interpreter"
-				VALUE "FileVersion", "1, 1, 51, 0"
+				VALUE "FileVersion", "1, 1, 52, 0"
 				VALUE "InternalName", "my_basic"
 				VALUE "LegalCopyright", "Copyright (C) 2011 - 2015 W. Renxin"
 				VALUE "LegalTrademarks", "MY-BASIC"
 				VALUE "OriginalFilename", "my_basic.exe"
 				VALUE "ProductName", "MY-BASIC"
-				VALUE "ProductVersion", "1, 1, 51, 0"
+				VALUE "ProductVersion", "1, 1, 52, 0"
 			END
 		END
 		BLOCK "VarFileInfo"
diff --git a/resource/resource.h b/resource/resource.h
old mode 100644
new mode 100755
diff --git a/shell/main.c b/shell/main.c
old mode 100644
new mode 100755
index 7ac6a75..a990d26
--- a/shell/main.c
+++ b/shell/main.c
@@ -304,6 +304,49 @@ static void _edit_program(const char* no) {
 	strcpy(c->lines[lno], line);
 }
 
+static void _insert_program(const char* no) {
+	char line[_MAX_LINE_LENGTH];
+	long lno = 0;
+	int i = 0;
+	mb_assert(no);
+	lno = atoi(no);
+	if(lno < 1 || lno > c->count) {
+		printf("Line number %ld out of bound.\n", lno);
+
+		return;
+	}
+	--lno;
+	memset(line, 0, _MAX_LINE_LENGTH);
+	printf("%ld]", lno + 1);
+	mb_gets(line, _MAX_LINE_LENGTH);
+	if(c->count + 1 == c->size) {
+		c->size += _LINE_INC_STEP;
+		c->lines = (char**)realloc(c->lines, sizeof(char*) * c->size);
+	}
+	for(i = c->count; i > lno; i--)
+		c->lines[i] = c->lines[i - 1];
+	c->lines[lno] = (char*)realloc(0, strlen(line) + 1);
+	strcpy(c->lines[lno], line);
+	c->count++;
+}
+
+static void _alter_program(const char* no) {
+	long lno = 0;
+	int i = 0;
+	mb_assert(no);
+	lno = atoi(no);
+	if(lno < 1 || lno > c->count) {
+		printf("Line number %ld out of bound.\n", lno);
+
+		return;
+	}
+	--lno;
+	free(c->lines[lno]);
+	for(i = lno; i < c->count - 1; i++)
+		c->lines[i] = c->lines[i + 1];
+	c->count--;
+}
+
 static void _load_program(const char* path) {
 	char* txt = _load_file(path);
 	if(txt) {
@@ -357,8 +400,10 @@ static void _show_help(void) {
 	printf("  BYE   - Quit interpreter\n");
 	printf("  LIST  - List current program\n");
 	printf("          Usage: LIST [l [n]], l is start line number, n is line count\n");
-	printf("  EDIT  - Edit a line in current program\n");
+	printf("  EDIT  - Edit (modify/insert/remove) a line in current program\n");
 	printf("          Usage: EDIT n, n is line number\n");
+	printf("                 EDIT -I n, insert a line before a given line, n is line number\n");
+	printf("                 EDIT -R n, remove a line, n is line number\n");
 	printf("  LOAD  - Load a file as current program\n");
 	printf("          Usage: LOAD *.*\n");
 	printf("  SAVE  - Save current program to a file\n");
@@ -407,7 +452,15 @@ static int _do_line(void) {
 		_list_program(sn, cn);
 	} else if(_str_eq(line, "EDIT")) {
 		char* no = line + strlen(line) + 1;
-		_edit_program(no);
+		char* ne = 0;
+		strtok(no, " ");
+		ne = no + strlen(no) + 1;
+		if(!(*ne))
+			_edit_program(no);
+		else if(_str_eq(no, "-I"))
+			_insert_program(ne);
+		else if(_str_eq(no, "-R"))
+			_alter_program(ne);
 	} else if(_str_eq(line, "LOAD")) {
 		char* path = line + strlen(line) + 1;
 		_load_program(path);