So far, we have looked at designing form layouts, adding form fields, creating and applying styles to form elements. Now we will learn to perform validations on the form fields. Let's learn how to add the validations for "Customer ID", which is a mandatory field in the customer form.

Select the input form field for "CustomerID".     Click on the "Validation" icon.     Only "Validation" option will be enabled. Click on the "Validation" option from the list.

"Data Validation" dialog box will be displayed.     To add validations, click on the "+" button; To make changes to an existing validation. click on the pen button. To delete an existing validation, click on the "-" button.     Data type validations are automatically performed by OrangeScape.     You can create your custom validations on data using the pen button.For example, text length for an input field can be validated to check if the user has entered data in the mandatory field. 'CustomerID" is a mandatory field. Check if text length is greater than zero to confirm if the user has entered a value for the field.     Criteria can be defined to control when a validation has to be performed. Criteria can be added by clicking on the define criteria "+" button.

Enter the criteria to define when the validation must be performed. No such validations are required for "CustomerID". Hence, the criteria need not be defined.