database. These controls automatically appear in the Form specified in its display control property and inherit many of the properties assigned to the field to which such controls are bound. Unbound controls display information to the user or get data from user that is not going to be stored in the database. A Calculated control is a special type of control, which displays the derived results of an expression or query.
The expression may consist of ready-to-use functions that are meant to make computations by using input values. Some commonly used functions have been discussed and described in Appendix given at the end of the chapter. Therefore, the data in calculated control cannot be modified because it is derived data or information. The value of these controls changes automatically as and when the data, to which the expression of the control is bound, changes.
Some of the common controls important for designing a Form are discussed below : (a) Label : This control is used to write dark prints on the Form such as Transaction Voucher, Voucher No, S.No, Debit, Credit, Amount, Narration, Authorised By, Prepared By on the left hand side and “Choose the Account to Debited” and “Choose the account to be Credited “on the right hand side of Access voucher Form design of which is shown in Fig . . The attached labels are automatically appended to the Form when other controls such as Text boxes, List boxes, Combo boxes, etc. are added because every such added control has to be labeled to inform the user as to what data to enter or edit through the control.
The default caption of the label is the caption of the field that underlies the control to which it is bound. If the caption property of the field is kept blank, the label caption uses field name as its caption. (b) Text Box : This control is included in a Form to provide a blank area for entering the data with or without default values. Blank space next to Amount label, for example, is a text box control to