Made changes to ch03.asciidoc

ch03.asciidoc

@@ -842,11 +842,12 @@ First, we use the +listunspent+ command to show all the unspent _confirmed_ outp
 ----
 $ bitcoin-cli listunspent 
 ----
-[source,json]
-----
+
+++++
+<screen language="json">
 [
     {
-        "txid" : "9ca8f969bd3ef5ec2a8685660fdbf7a8bd365524c2e1fc66c309acbae2c14ae3",
+        "txid" : "9ca8f969bd3ef5ec2a8685660fdbf7a8bd365524c2e1fc66c309acbae2c<?pdf-cr?>14ae3",
         "vout" : 0,
         "address" : "1hvzSofGwT8cjb8JU7nBsCSfEVQX5u9CL",
         "account" : "",
@@ -855,7 +856,8 @@ $ bitcoin-cli listunspent
         "confirmations" : 7
     }
 ]
-----
+</screen>
+++++
 
 We see that the transaction +9ca8f9...+ created an output (with vout index 0) assigned to the address +1hvzSo...+ for the amount of 50 millibits, which at this point has received seven confirmations. Transactions use previously created outputs as their inputs by referring to them by the previous txid and vout index. We will now create a transaction that will spend the 0th vout of the txid +9ca8f9...+ as its input and assign it to a new output that sends value to a new address.