I have to create a code that would be used in a company who creates website penetration testers. So far this is the code I have. How would you make it better?

Open to all possibilities.

Code:

integer userlD

integer x

integer userPass

integer array$(5)$ userGroup

$//$ IDs will only accept five digit combinations

for x $=0$; x $<$ userGroup.size; x$=$ x $+1$

userGroup$[$x$]=$ Get next input

if userGroup$[$x$]>=100000$ and userGroup$[$x$]<=999999$

Put userGroup$[$x$]$ to output

else

Put "Invalid user IDin" to output

if userGroup$[$x$]>=100000$ and userGroup$[$x$]<=999999$

Put $"$ is$"$ to output

if userGroup$[$x$]\%5==0$

Put "invalid for buying without paying"to output

$//$ IDs divisible by $5$ are marked as invalid

else

Put "a valid clientid" to output