any help on impersonation

Question

Hi

I have a web application running on the hosting server. I want to used the code below to perform impersonation, but I am confused where do I get the user,domain and password to supply of the said parameters of LogonUser function. Is this our server account in the hosting server or is this coming from custom identity(form authentication) that I have created?

LogonUser("user","domain","password", LOGON32_LOGON_NETWORK,LOGON32_PROVIDER_DEFAULT, out lnToken);