Click the field tool 
or the variable tool 
in
the toolbar at the top of the editor window.
Click and drag to define a rectangle in which to display the value.
When you release the mouse button, a window will appear.
Select the desired values from the Select Table and Select Field lists if present or select the desired value from the Variable pop up menu.
For dates and numbers, if desired, select a format from the Display Format pop up menu.
For monetary values, you can insert a dollar sign at the beginning of the selected format by typing it into the Format field.
Click the OK button.