Change Item Quantity on Equip

001208b8: 308403ff andi r4,r4,0x03ff
001208bc: 1080000c beq r4,r0,0x001208f0		branch if item ID = 0
001208c0: 00001021 addu r2,r0,r0			return r2 = 0
001208c4: 3c018006 lui r1,0x8006
001208c8: 00240821 addu r1,r1,r4
001208cc: 902296e0 lbu r2,-0x6920(r1)			load item's quantity
001208d0: 00000000 nop
001208d4: 00451021 addu r2,r2,r5			change item quantity by r5
001208d8: 04410002 bgez r2,0x001208e4			branch if item quantity is legal
001208dc: 00000000 nop
001208e0: 00001021 addu r2,r0,r0			if item amount <=0, set item quantity to 0
001208e4: 3c018006 lui r1,0x8006
001208e8: 00240821 addu r1,r1,r4
001208ec: a02296e0 sb r2,-0x6920(r1)			store new item quantity
001208f0: 03e00008 jr r31
001208f4: 00000000 nop