Update date column with number of days in another column using vba

Hello all
i have a table with 10 columns and last four are date columns i.e. G H I & J.
Last three have formula
column B require input from user for in number and column G require date.
Column H is simple addition of Column B & G
for example if B has value 5 and G has 1 Apr 17 then H will be 6 Apr 17. this is easy with formula but i want to achieve this with vba.
can anyone help please.
Thanks

hi Yasser thanks it gives result as required, but code is stuck in loop.. something to come out of loop..

thanks again

hi Yasser i got it right with selection change event. i am attaching the file with formulas but i want to achieve this with vba. help is appreciated.
heading are
(to be entered by user)
B = Number of days (has to be number)
C = PF means Prefix
D = IF i.e. Interfix
E = SF i.e. Suffix
F = JP i.e. journey period
G = Departure date
calculated fields
H = Start Date i.e. H + C
I = End Date i.e. B+D+E+F
J = Reporting Date i.e. if F is empty(no JP) then I + 1 else I
thanks again

the file could not attach earlier.

one more problem, the code is working fine in first row but doesnt work in following rows.
i modified the code to add I column also.

Thanks