ERROR: no rrdtool fetch output, you probably forgot to pass

[on-site]

ERROR: no rrdtool fetch output, you probably forgot to pass a valid data source

I have followed a couple of different walk throughs and when ever I create a new graph it always shows up as a red x and then the above error.

Any help would be appreciated.

Michael

[on-site]

Does any body have any sugestions or am I not giving enough information about my setup...?