One of the first fields on my form needs to be unique (FieldA), and the form itself is rather long. If a user enters a value into FieldA that is not unique, they get an error message, but not until they try to submit the form.
How can I have the the error message ("Value already present") appear as soon as the user clicks out of that field - using onblur in javascript, for example - rather than waiting until the user hits the submit button? I sought out information on the internet but have not found a suitable solution to this problem. I am trying to prevent users wasting time filling out the entire form so that they are alerted of the error immediately upon entering the non-unique value.
Thanks so much for the help.