@servicenow14710 : We cannot restrict submissions using the onChange client script. It can be done only via the OnSubmit client script.
onChange()
An onChange() script can run when a particular field changes value or when the form is first drawn and no fields have changed value from previous script actions. As such, onChange scripts can potentially act as onLoad scripts with extra conditions.
onSubmit()
An onSubmit() script runs when a form is submitted. Typically, you use an onSubmit() script to validate things on the form and ensure that the submission makes sense. As such, onSubmit() scripts can potentially cancel a submission by returning false.
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