You can make a code based on a special code word which only you know about. We've chosen the word "XYLOPHONE". So first of all we write down the normal alphabet (it's called the Plain Text alphabet), and below it we write the Code alphabet, starting with the codeword, and following the codeword with the rest of the alphabet.
But there's a trick to this - remember that you don't want repeated letters! So you have to leave out the seond O in XYLOPHONE, and when you get to the normal alphabet you write down ABCDFGI... leaving out the E, the H, and any other letters in the codeword.
So here's what the alphabet looks like when you're finished:
Plain text: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Code: X Y L O P H N E A B C D F G I J K M Q R S T U V W Z
When you're solving this code, remember to look up the letter in the Code alphabet. So the letter S is decoded as U, because U is above S.
QLISR is decoded as SCOUT
Codeword XYLOPHONE
YMAGN WISM YALWLDP XGO X YXLCJXLC
Codeword SMYTHE
PYKRQ SPPKYCSQCKJ KE PKRQB SEOCYS