hi, is there anyone could redirect me to the explanation of "how can I set msg.value in web3js " or simply tell? I can interact to the contract totally but i don't know how to get/set value at msg.value in the dapp

That's the amount of Ethers you send in the transaction (not to be confused with gas things). You can't set it explicitly. If you don't send any Ethers, the value is 0

thanks. the problem is i can't find how to reach to that value via web3js.

to send Ethers in a transaction you can do something like contr.someFunc(someParam, {value: amountInWeis} )

I've got a deposit function uses msg.value. should I write a transaction function to run deposit function, you suggest?

no, just call the deposit function from your web3 code

web3.eth.sendTransaction({from: someAddress, to: someAddress, value: web3.utils.toWei(“1”, “ether”)})

I'm testing this, thanks... @sleepstntnc

thank you, too @Lauri_P

I m sorry

Corrected to the newer version

If u want to send on the contract

Use @Lauri_P example

well the things is i just need to pass a value that I got from input element to the network as msg.value, I'm building a dapp on someone else's contract, their deposit function doesn't have a getter value parameter, it uses msg.value only. i think it's best to send transaction to the contract manually to realize the deposit.