When we are developing BSP application consists of several UI elements in the form,usually we will write java script validations to validate the data in the form.Assume we also have a submit button in the form and validating all the form fields data when we press the submit button.Here the problem lies,though we validate and showing the alert message server event will trigger and save the junk data to the data base.
To supress the server event and validate the form use the below statement.
htmlbevent.cancelSubmit = true; " it will cancel the server event when java script validation return false.