diff --git a/gnu/lib/libdialog/checklist.c b/gnu/lib/libdialog/checklist.c
index cc83d258b5f..f33dfc231fd 100644
--- a/gnu/lib/libdialog/checklist.c
+++ b/gnu/lib/libdialog/checklist.c
@@ -34,7 +34,7 @@ static int list_width, check_x, item_x;
  */
 int dialog_checklist(unsigned char *title, unsigned char *prompt, int height, int width, int list_height, int item_no, unsigned char **items, unsigned char *result)
 {
-  int i, x, y, cur_x, cur_y, box_x, box_y, key = 0, button = 0, choice = 0,
+  int i, j, x, y, cur_x, cur_y, box_x, box_y, key = 0, button = 0, choice = 0,
       scroll = 0, max_choice, *status;
   WINDOW *dialog, *list;
 
@@ -50,6 +50,22 @@ int dialog_checklist(unsigned char *title, unsigned char *prompt, int height, in
 
   max_choice = MIN(list_height, item_no);
 
+  check_x = 0;
+  item_x = 0;
+  /* Find length of longest item in order to center checklist */
+  for (i = 0; i < item_no; i++) {
+    check_x = MAX(check_x, strlen(items[i*3]) + strlen(items[i*3 + 1]) + 6);
+    item_x = MAX(item_x, strlen(items[i*3]));
+  }
+  if (height < 0)
+	height = strheight(prompt)+list_height+4+2;
+  if (width < 0) {
+	i = strwidth(prompt);
+	j = strwidth(title);
+	width = MAX(i,j);
+	width = MAX(width,check_x+10)+4;
+  }
+
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/dialog.h b/gnu/lib/libdialog/dialog.h
index f2b5d691bee..cb7053f1378 100644
--- a/gnu/lib/libdialog/dialog.h
+++ b/gnu/lib/libdialog/dialog.h
@@ -80,15 +80,17 @@ void draw_shadow(WINDOW *win, int y, int x, int height, int width);
 #endif
 void draw_box(WINDOW *win, int y, int x, int height, int width, chtype box, chtype border);
 int line_edit(WINDOW* dialog, int box_y, int box_x, int box_width, chtype attrs, int first, unsigned char *result);
+int     strheight(const char *p);
+int     strwidth(const char *p);
 
 void dialog_create_rc(unsigned char *filename);
 int dialog_yesno(unsigned char *title, unsigned char *prompt, int height, int width);
-int dialog_prgbox(unsigned char *title, const char *line, int height, int width, int pause, int use_shell);
+int dialog_prgbox(unsigned char *title, const unsigned char *line, int height, int width, int pause, int use_shell);
 int dialog_msgbox(unsigned char *title, unsigned char *prompt, int height, int width, int pause);
 int dialog_textbox(unsigned char *title, unsigned char *file, int height, int width);
 int dialog_menu(unsigned char *title, unsigned char *prompt, int height, int width, int menu_height, int item_no, unsigned char **items, unsigned char *result);
 int dialog_checklist(unsigned char *title, unsigned char *prompt, int height, int width, int list_height, int item_no, unsigned char **items, unsigned char *result);
-int dialog_radiolist(char *title, char *prompt, int height, int width, int list_height, int item_no, unsigned char **items, unsigned char *result);
+int dialog_radiolist(unsigned char *title, unsigned char *prompt, int height, int width, int list_height, int item_no, unsigned char **items, unsigned char *result);
 int dialog_inputbox(unsigned char *title, unsigned char *prompt, int height, int width, unsigned char *result);
 void dialog_clear(void);
 void dialog_update(void);
diff --git a/gnu/lib/libdialog/inputbox.c b/gnu/lib/libdialog/inputbox.c
index 197b4dfaedf..11e3566580e 100644
--- a/gnu/lib/libdialog/inputbox.c
+++ b/gnu/lib/libdialog/inputbox.c
@@ -28,11 +28,19 @@
  */
 int dialog_inputbox(unsigned char *title, unsigned char *prompt, int height, int width, unsigned char *result)
 {
-  int i, x, y, box_y, box_x, box_width, first,
+  int i, j, x, y, box_y, box_x, box_width, first,
       key = 0, button = -1;
   unsigned char instr[MAX_LEN+1];
   WINDOW *dialog;
 
+  if (height < 0)
+	height = strheight(prompt)+2+4;
+  if (width < 0) {
+	i = strwidth(prompt);
+	j = strwidth(title);
+	width = MAX(i,j) + 4;
+  }
+
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/kernel.c b/gnu/lib/libdialog/kernel.c
index 4e30c51372a..9309fecd168 100644
--- a/gnu/lib/libdialog/kernel.c
+++ b/gnu/lib/libdialog/kernel.c
@@ -422,3 +422,53 @@ void end_dialog(void)
 {
     endwin();
 }
+
+int strwidth(const char *p)
+{
+	int i = 0, len, incr;
+	const char *start, *s, *s1, *s2;
+
+	for (start = s = p; ; start = (s += incr)) {
+		s1 = strchr(s, '\n');
+		s2 = strstr(s, "\\n");
+		if (s2 == NULL)
+			s = s1;
+		else if (s1 == NULL)
+			s = s2;
+		else
+			s = MIN(s1, s2);
+		if (s == NULL)
+			break;
+		incr = 1 + (s == s2);
+		len = s - start;
+		if (len > i)
+			i = len;
+	}
+	len = strlen(start);
+	if (len > i)
+		i = len;
+	return i;
+}
+
+int strheight(const char *p)
+{
+	int i = 1, incr;
+	const char *s, *s1, *s2;
+
+	for (s = p; ; s += incr) {
+		s1 = strchr(s, '\n');
+		s2 = strstr(s, "\\n");
+		if (s2 == NULL)
+			s = s1;
+		else if (s1 == NULL)
+			s = s2;
+		else
+			s = MIN(s1, s2);
+		if (s == NULL)
+			break;
+		incr = 1 + (s == s2);
+		i++;
+	}
+	return i;
+}
+
diff --git a/gnu/lib/libdialog/menubox.c b/gnu/lib/libdialog/menubox.c
index 5aa5b5b1116..3dd29e862c1 100644
--- a/gnu/lib/libdialog/menubox.c
+++ b/gnu/lib/libdialog/menubox.c
@@ -34,12 +34,28 @@ static int menu_width, tag_x, item_x;
  */
 int dialog_menu(unsigned char *title, unsigned char *prompt, int height, int width, int menu_height, int item_no, unsigned char **items, unsigned char *result)
 {
-  int i, x, y, cur_x, cur_y, box_x, box_y, key = 0, button = 0, choice = 0,
+  int i, j, x, y, cur_x, cur_y, box_x, box_y, key = 0, button = 0, choice = 0,
       scroll = 0, max_choice;
   WINDOW *dialog, *menu;
 
   max_choice = MIN(menu_height, item_no);
 
+  tag_x = 0;
+  item_x = 0;
+  /* Find length of longest item in order to center menu */
+  for (i = 0; i < item_no; i++) {
+    tag_x = MAX(tag_x, strlen(items[i*2]) + strlen(items[i*2 + 1]) + 2);
+    item_x = MAX(item_x, strlen(items[i*2]));
+  }
+  if (height < 0)
+	height = strheight(prompt)+menu_height+4+2;
+  if (width < 0) {
+	i = strwidth(prompt);
+	j = strwidth(title);
+	width = MAX(i,j);
+	width = MAX(width,tag_x+4)+4;
+  }
+
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
@@ -96,13 +112,6 @@ int dialog_menu(unsigned char *title, unsigned char *prompt, int height, int wid
   /* draw a box around the menu items */
   draw_box(dialog, box_y, box_x, menu_height+2, menu_width+2, menubox_border_attr, menubox_attr);
 
-  tag_x = 0;
-  item_x = 0;
-  /* Find length of longest item in order to center menu */
-  for (i = 0; i < item_no; i++) {
-    tag_x = MAX(tag_x, strlen(items[i*2]) + strlen(items[i*2 + 1]) + 2);
-    item_x = MAX(item_x, strlen(items[i*2]));
-  }
   tag_x = (menu_width - tag_x) / 2;
   item_x = tag_x + item_x + 2;
 
diff --git a/gnu/lib/libdialog/msgbox.c b/gnu/lib/libdialog/msgbox.c
index e405f3b5a26..fda3b40641a 100644
--- a/gnu/lib/libdialog/msgbox.c
+++ b/gnu/lib/libdialog/msgbox.c
@@ -29,9 +29,17 @@
  */
 int dialog_msgbox(unsigned char *title, unsigned char *prompt, int height, int width, int pause)
 {
-  int i, x, y, key = 0;
+  int i, j, x, y, key = 0;
   WINDOW *dialog;
 
+  if (height < 0)
+	height = strheight(prompt)+2+2*(!!pause);
+  if (width < 0) {
+	i = strwidth(prompt);
+	j = strwidth(title);
+	width = MAX(i,j)+4;
+  }
+
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/prgbox.c b/gnu/lib/libdialog/prgbox.c
index db825890a30..67260999554 100644
--- a/gnu/lib/libdialog/prgbox.c
+++ b/gnu/lib/libdialog/prgbox.c
@@ -27,7 +27,7 @@
  * Display a message box. Program will pause and display an "OK" button
  * if the parameter 'pause' is non-zero.
  */
-int dialog_prgbox(unsigned char *title, const char *line, int height, int width, int pause, int use_shell)
+int dialog_prgbox(unsigned char *title, const unsigned char *line, int height, int width, int pause, int use_shell)
 {
   int i, x, y, key = 0;
   WINDOW *dialog;
diff --git a/gnu/lib/libdialog/radiolist.c b/gnu/lib/libdialog/radiolist.c
index 5a2151861d8..8b1cf3c72c0 100644
--- a/gnu/lib/libdialog/radiolist.c
+++ b/gnu/lib/libdialog/radiolist.c
@@ -33,9 +33,9 @@ static int list_width, check_x, item_x;
 /*
  * Display a dialog box with a list of options that can be turned on or off
  */
-int dialog_radiolist(char *title, char *prompt, int height, int width, int list_height, int item_no, unsigned char **items, unsigned char *result)
+int dialog_radiolist(unsigned char *title, unsigned char *prompt, int height, int width, int list_height, int item_no, unsigned char **items, unsigned char *result)
 {
-  int i, x, y, cur_x, cur_y, box_x, box_y, key = 0, button = 0, choice = 0,
+  int i, j, x, y, cur_x, cur_y, box_x, box_y, key = 0, button = 0, choice = 0,
       scroll = 0, max_choice, *status, was_on = 0;
   WINDOW *dialog, *list;
 
@@ -58,6 +58,22 @@ int dialog_radiolist(char *title, char *prompt, int height, int width, int list_
   }
   max_choice = MIN(list_height, item_no);
 
+  check_x = 0;
+  item_x = 0;
+  /* Find length of longest item in order to center radiolist */
+  for (i = 0; i < item_no; i++) {
+    check_x = MAX(check_x, strlen(items[i*3]) + strlen(items[i*3 + 1]) + 6);
+    item_x = MAX(item_x, strlen(items[i*3]));
+  }
+  if (height < 0)
+	height = strheight(prompt)+list_height+4+2;
+  if (width < 0) {
+	i = strwidth(prompt);
+	j = strwidth(title);
+	width = MAX(i,j);
+	width = MAX(width,check_x+10)+4;
+  }
+
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
@@ -114,13 +130,6 @@ int dialog_radiolist(char *title, char *prompt, int height, int width, int list_
   /* draw a box around the list items */
   draw_box(dialog, box_y, box_x, list_height+2, list_width+2, menubox_border_attr, menubox_attr);
 
-  check_x = 0;
-  item_x = 0;
-  /* Find length of longest item in order to center radiolist */
-  for (i = 0; i < item_no; i++) {
-    check_x = MAX(check_x, strlen(items[i*3]) + strlen(items[i*3 + 1]) + 6);
-    item_x = MAX(item_x, strlen(items[i*3]));
-  }
   check_x = (list_width - check_x) / 2;
   item_x = check_x + item_x + 6;
 
diff --git a/gnu/lib/libdialog/yesno.c b/gnu/lib/libdialog/yesno.c
index 3f21b5a7d58..1e4f77db4b1 100644
--- a/gnu/lib/libdialog/yesno.c
+++ b/gnu/lib/libdialog/yesno.c
@@ -28,9 +28,17 @@
  */
 int dialog_yesno(unsigned char *title, unsigned char * prompt, int height, int width)
 {
-  int i, x, y, key = 0, button = 0;
+  int i, j, x, y, key = 0, button = 0;
   WINDOW *dialog;
 
+  if (height < 0)
+	height = strheight(prompt)+4;
+  if (width < 0) {
+	i = strwidth(prompt);
+	j = strwidth(title);
+	width = MAX(i,j)+4;
+  }
+
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;