Program:  Superbase 4
    Version:  1.3x
    Topic:    Setting up a form with a calculated default value
    Date:     10/13/92

    Summary:  This technote explains how to set up a form that shows a
    calculated default value that appears when the cursor first enters
    the field.  This value can be modified and written to a field.
    This process is separated into the following steps:  setting up
    the data file, initially setting up the form,  and calculating the
    value.

    Application:  In an order form, the default value for Extended
    Price would be Price * Units.  However, this value may be changed
    due to special discounts, negotiations, etc.  When data is being
    entered, the user sees the default value after he enters the Price
    and Units, before the cursor moves past the Extended Price field.
    He can then change this value, and it is stored in the Extended
    Price field.  Once a value has been entered into this field, it
    won't be recalculated.

    Setting up the data file

    Create an Orders file that contains the following fields:
    Orderno, Price, Units, ExtPrice.

    1.  Run Superbase, and select File, New to create a new file.
    2.  Orderno may be a text or numeric field.
    3.  Add Price, Units, and ExtPrice as numeric fields.  Do not make
        them calculated.

    Setting up the form

    Create a form.

    1.  Run the Form Designer, and use File, New to create a
        form.
    2.  Use File, SB File Open to open the orders file.
    3.  Use the FLD tool and place the Orderno, Price, Units, and
        ExtPrice
        fields on the form.

    Calculating the value

    Use the CLC tool to define the calculation for ExtPrice.

    1.  Select the CLC tool with your left mouse button.
    2.  Put the CLC between Units and ExtPrice.
    3.  Give the CLC a name -- it should be a numeric variable, like
        ltot%.
    4.  For the calculation formula, enter:
        LET ExtPrice.orders = (ExtPrice.orders = 0) ? Price.orders *
        Units.orders : ExtPrice.orders

    If ExtPrice has a value entered previously, it will appear.
    Otherwise, the result of Price * Units will appear in the ExtPrice
    field.

    5.  You can change the background and foreground color of the CLC
        so it is hidden on the form.