No, you have to use electronic flux, not plumbing flux. :)
Plumbing flux will corrode the connection over time, it's acid based. Electronic flux is rosin based.
You can buy electronic flux at Radio shack.
Yup. Patrick's right.
Also, be sure to only use a Rosin core solder as well. Might sound obvious, but I've seen countless people use acidcore. That stuff will have you coughing for hours...