curl through proxy syntax

I don't understand how to read this general syntax. I want to request a URL through our proxy and it requires a specific host, port, username, and password. I don't know how to figure out what the protocol is. I want to do curl through a proxy. Based on the helpfile below, I would guess the line should be: curl -x [whatever-my-protocol-is://]my-host-which-i-know[:my-port-which-i-know] -U my-username-which-i-know[:my-pass-which-i-know] http://www.google.com Is this right? How do I figure out the protocol? Relevant info from man: ``` -x, --proxy [PROTOCOL://]HOST[:PORT] Use proxy on given port --proxy-anyauth Pick "any" proxy authentication method (H) --proxy-basic Use Basic authentication on the proxy (H) --proxy-digest Use Digest authentication on the proxy (H) --proxy-negotiate Use Negotiate authentication on the proxy (H) --proxy-ntlm Use NTLM authentication on the proxy (H) -U, --proxy-user USER[:PASSWORD] Proxy user and password --proxy1.0 HOST[:PORT] Use HTTP/1.0 proxy on given port ```