I tried this method, but in order to do that, I have to comment out the USART_Receive function and define a value for 'info'. If I don't do that, the compiler will wait at code
info = USART_Receive();
function in order to assign data to 'info'.

So set a breakpoint after that.... you just need to see what is being evaluated in your if statement....

 

I tried this method, but in order to do that, I have to comment out the USART_Receive function and define a value for 'info'. If I don't do that, the compiler will wait at code
info = USART_Receive();
function in order to assign data to 'info'.

You are accomplishing nothing when you do that. You really need to learn to use your debugger. Before going any further read up on how to use the debugger.

Once the debugger stops you can continue again. You should also be able to set a breakpoint then a variable reaches a certain value or the breakpoint is passed a set amount of times.

 

Don't know if your mcu has an rs232 out for debug but you can also debug the old fashioned way by printing values to the terminal.

 

I added a watch point in the if statement, but I can not see the value of variable 'info', which shows 'optimized away'.

 

Then try simply echoing the received data back to the terminal.
Also, did you correct the led off statement?

 

I added a watch point in the if statement, but I can not see the value of variable 'info', which shows 'optimized away'.

info was optimized out!? try making info a volatile int.....