Batch file terminates unexpectedly when enter key is pressed

Question

I am currently writing a batch file to get users to enter the telephone's serial number. I have written the following:

set /p sernumoftel1="Enter Serial Number of the First Telephone: "
set /p sernumoftel2="Enter Serial Number of the Second Telephone (Press Enter Key To Skip If You DO NOT HAVE A Second Telephone): "

if not %sernumoftel1% == "" (
echo. > soe.txt
echo Serial Number of Telephone 1: >> soe.txt
echo %sernumoftel1% >> soe.txt
)


if not %sernumoftel2% == "" (
echo. >> soe.txt
echo Serial Number of Telephone 2: >> soe.txt
echo %sernumoftel2% >> soe.txt
)

echo You Are Done!
pause

However, at the second question, when I pressed the enter key, command prompt exited unexpectedly, without displaying 'You Are Done!'.

What did I do wrong? Any help is appericiated.

Answer 1

Use quotes on if statements

if not "%sernumoftel1%" == "" (....


if not "%sernumoftel2%" == "" (...

Answer 2

You can also look into making sure the variable is defined after set /p.

 if not defined variable (
   echo Error: Variable empty!
   pause && exit
)