This command will create a selectable menu for the invoking character. Only one
menu can be on screen at the same time.

Depending on what the player picks from the menu, the script execution will
continue from the corresponding label. (it's string-label pairs, not label-
string)

It also sets a special temporary character variable @menu, which contains the
number of option the player picked. (Numbering of options starts at 1.)

menu "I want to Start",L_Start,"I want to end",L_End;
L_Start:
//If they click "I want to Start" they will end up here
L_End:
//If they click "I want to end" they will end up here

If a label is '-', the script execution will continue right after the menu
command if that option is selected, this can be used to save you time, and
optimize big scripts.

menu "I want to Start",-,"I want to end",L_End;
//If they click "I want to Start" they will end up here
L_End:
//If they click "I want to end" they will end up here

Both these examples will perform the same task.

If you give an empty string as a menu item, the item will not display. This
can effectively be used to script dynamic menus by using empty string for
entries that should be unavailable at that time.

You can do it by using arrays, but watch carefully - this trick isn't high
wizardry, but minor magic at least. You can't expect to easily duplicate it
until you understand how it works.

Create a temporary array of strings to contain your menu items, and populate it
with the strings that should go into the menu at this execution, making sure not
to leave any gaps. Normally, you do it with a loop and an extra counter, like
this:

setarray @possiblemenuitems$[0],<list of potential menu items>;
set @i,0; // That's our loop counter.
set @j,0; // That's the menu lines counter.

makemenuloop:

// We record the number of option into the list of options actually
// available. That 'condition' is whatever condition that determines whether
// a menu item number @i actually goes into the menu or not.

if (<condition>) set @menulist$[@j],@possiblemenuitems$[@i];

// We just copied the string, we do need it's number for later though, so we
// file it away as well.

if (<condition>) set @menureference[@j],@i;

// Since we've just added a menu item into the list, we increment the menu
// lines counter.

if (<condition>) set @j,@j+1;

// We go on to the next possible menu item.

set @i,@i+1;

// And continue looping through the list of possible menu items until it
// ends.

if (@i<=getarraysize(@possiblemenuitems)) goto makemenuloop;


This will create you an array @menulist$ which contains the text of all items
that should actually go into the menu based on your condition, and an array
@menureference, which contains their numbers in the list of possible menu items.
(Remember, arrays start with 0.) There's less of them than the possible menu
items you've defined, but the menu command can handle the empty lines - only if
they are last in the list, and if it's made this way, they are. Now comes a

// X is whatever the most menu items you expect to handle.
dirty trick:
menu @menulist$[0],-,@menulist$[1],-,....@menulist$[<X>],-;

This calls up a menu of all your items. Since you didn't copy some of the
possible menu items into the list, it's end is empty and so no menu items will
show up past the end. But this menu call doesn't jump anywhere, it just
continues execution right after the menu command. (And it's a good thing it
doesn't, cause you can only explicitly define labels to jump to, and how do you
know which ones to define if you don't know beforehand which options will end up
where in your menu?)
But how do you figure out which option the user picked? Enter the @menu.

@menu contains the number of option that the user selected from the list,
starting with 1 for the first option. You know now which option the user picked
and which number in your real list of possible menu items it translated to:

mes "You selected "+@possiblemenuitems$[@menureference[@menu-1]]+"!";

@menu is the number of option the user picked.
@menu-1 is the array index for the list of actually used menu items that we
made.
@menureference[@menu-1] is the number of the item in the array of possible menu
items that we've saved just for this purpose.

And @possiblemenuitems$[@menureference[@menu-1]] is the string that we used to
display the menu line the user picked. (Yes, it's a handful, but it works.)

You can set up a bunch of 'if (@menureference[@menu-1]==X) goto Y' statements to
route your execution based on the line selected and still generate a different
menu every time, which is handy when you want to, for example, make users select
items in any specific order before proceeding, or make a randomly shuffled menu.

Kafra code bundled with the standard distribution uses a similar array-based
menu technique for teleport lists, but it's much simpler and doesn't use @menu,
probably since that wasn't documented anywhere.

See also 'select', which is probably better in this particular case. Instead of
menu, you could use 'select' like this:

set @dummy,select(@menulist$[0],@menulist$[1],....@menulist$[<X>]);

For the purposes of the technique described above these two statements are
perfectly equivalent.