If msg.value is specified in a call such as “msg.sender.call.value(msg.value)” then where is msg.value taken from, when this is from contract?

I mean in this case: function x(address receiver) { receiver.call.value(msg.value)(); } So receiver can be any address but msg.value cannot be controlled via argument? Does this mean that msg.value will always be zero or will it be taken from the msg.sender? Thanx!

Truffle Error: ContractName has no network configuration for its current network id (1575203139857)

Im doing the tutorial at https://github.com/ConsenSys-Academy/proof-of-existence-exercise and running into the following error: $ truffle console truffle(development)> var poe = await ProofOfExistence2.at(ProofOfExistence2.address) Thrown: Error: ProofOfExistence2 has no network configuration for its current network id (1575203139857). at evalmachine.<anonymous>:1:48 at Function.getter (C:\Users\mrleo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\contract\lib\contract\constructorMethods.js:243:1) at Function.get (C:\Users\mrleo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\contract\lib\contract\properties.js:129:1) at Function.getter (C:\Users\mrleo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\contract\lib\contract\constructorMethods.js:246:1) at Function.network (C:\Users\mrleo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\contract\lib\contract\properties.js:108:1) truffle(development)> truffle(development)>

If you need a server to store HTML and java script code, then what is the use of the block chain?

I have been studying block chain for a while, and I came to know that decentralisation of data is its greatest pros. From my understanding, if block chain is massively adopted in the future, we will no longer need servers, since everything will be stored on the block chain. Currently, we can store solidity smart…