LCD menu in C?

/* global variables */
Uint8 display_buffer[NBR_LINES][NBR_CHARS_PER_LINE];
Int8 selected_item;

void Init_Menu( void )
{
Uint8 line;

   // Init the display lines with whatever you want them to say
   for (line = 0; line < NBR_LINES; line++)
      sprintf(display_buffer[line], "  Menu Item %d", line);
}

void Service_Selected_Item( Uint8 cmd )
{
   // This function allows the user to change the selected menu item
   switch (cmd)
   {
      case INCREMENT_SELECTION:
         selected_item++;
         if (selected_item > NBR_LINES)
            selected_item = 0;
         break;
      
      case DECREMENT_SELECTION:
         selected_item--;
         if (selected_item < 0)
            selected_item = NBR_LINES - 1;
         break;
   }
}

void Service_Display( cmd )
{
   switch ( cmd )
   {
      case DRAW_MENU:
         Init_Menu();
         /* Each line now contains some text that the user can read to decide what he wants to select.  Insert a character into the appropriate line to allow the user to know which item is selected */
         display_buffer[selected_item][0] = '>';
         Update_Display();
         break;

      case SOME_OTHER_DISPLAY_STATE:
         break;
   }
}