How to change MID?

[flamyman1412 4]

local MID = GetChaID(dead)
    if(MID == 1)then
        local fame         = GetChaAttr( atk , ATTR_FAME )
        local famebonus = 100
        fame = fame + famebonus
        SetCharaAttr( fame, atk , ATTR_FAME )
    elseif(MID == 2) then
        BickerNotice(atk,'Find a refining gem!')    
        GiveItem(atk, 885 , 1, 4 )        
    end

 

I will adjust to a monster. All in game?
What is the function?

[DangThao 81]

MID is used to called the deadmonster id and this can be placed inside your server file > resource > script > calculate > exp_and_level.lua; find function GetExp_New(dead , atk  ) 
and place it near the end of this function.