Default [Q] How do i fix this On My Zenphone 4 : There Is No su binary installed

I have rooted my zenphone 4 . . And i dont know what software i have used to root my device . . But its rooted . . And after i update the system . . And i run the superusers . . This thing come out "there is no su binary installed , and superusers cannot install it .this is a problem . . .if you just upgrade to android 4.3 , you need to manually reroot . Consult the relevant forums for you device" what should i do . . Help me plsss urgent . Thanks a lot . . It could be better if u teach me step by step .