You can't nest id's that deeply so another way is a table like this
Col A Col B
100 aa
101 bb
102 cc
103 dd
104 ee
105 ff
106 gg
107 hh
108 ii
109 jj
110 kk
111 ll
Column A are your ID No's and Column B are names. The formula
=VLOOKUP(C1,A1:B12,2,FALSE)
Looks for the ID No in C1 in Column A and returns the corresponding name
form Column B
You should not be using IF for that number of tests.
Use Vlookup instead.
With a list of Employee numbers in column A and Employee Names in column B,
and with the Employee number to be looked up in C1, enter in D1
=VLOOKUP(C1,$A:$B,2,0)
and that will return the Employee's name