My random combat wont work! help! Also, my Load thingy wont work...I keep getting runtaime errors....Heres the rand combat:

turf //the ground icons
grass
icon='grass.dmi'
Entered()
if(istype(usr,/mob/Merc))
var/chancetofight=rand(1,100) //randomly pick a number
switch(chancetofight) //change it to make it easier to check
if(1)
usr.battle(/mob/monsters/slime) //starts the fight... same for
// below
if(11)
usr.battle(/mob/monsters/redslime)
if(21)
usr.battle(/mob/monsters/slime)
if(31)
usr.battle(/mob/monsters/redslime)
if(41)
usr.battle(/mob/monsters/slime)
if(51)
usr.battle(/mob/monsters/redslime)
if(51)
usr.battle(/mob/monsters/slime)
if(61)
usr.battle(/mob/monsters/redslime)
if(71)
usr.battle(/mob/monsters/slime)
if(81)
usr.battle(/mob/monsters/redslime)
if(91)
usr.battle(/mob/monsters/slime)
if(istype(usr,/mob/Hero))
var/chancetofight=rand(1,100) //randomly pick a number
switch(chancetofight)
if(1)
usr.battle(/mob/monsters/slime)
if(11)
usr.battle(/mob/monsters/redslime)
if(21)
usr.battle(/mob/monsters/slime)
if(31)
usr.battle(/mob/monsters/redslime)
if(41)
usr.battle(/mob/monsters/slime)
if(51)
usr.battle(/mob/monsters/redslime)
if(51)
usr.battle(/mob/monsters/slime)
if(61)
usr.battle(/mob/monsters/redslime)
if(71)
usr.battle(/mob/monsters/slime)
if(81)
usr.battle(/mob/monsters/redslime)
if(91)
usr.battle(/mob/monsters/slime)

batloc //where the battles take place
icon='grass.dmi'
invisibility=101 //set it so you can only see them in the map editor
invisiblewall //stops you from walking where you don't want to walk
density=1


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