Creating report

[mattpv]

I have created a report via design view and I did not specify a table to pull information from but I do need to have info. from a table (control source) text box properties. My question is how or what phrase do you need in order to have the info pulled from a table. ex: when you click the build button under properties for a text box. I double clicked the table name, and then the data field I want the data to come from but it does not work. It shows #Name? on the report.
code looks like so:
=[Final00]![File_NO] What do I need in front of it to work?

All help appreciated!