I have a basic PDF form (textboxes, checkboxes) that users fill out, then this form gets uploaded to a custom software solution. The problem I'm having is, I'd like to require a field, such as a textbox, to be filled out BEFORE the user can close the form. In other words, when the user tries to close this form (which is opened in Adobe Reader 9) the form should validate that a value has been entered in a textbox that I specify. If the textbox is blank/null, then the user should be alerted and the form should remain open. Anyone have any experience with this sort of functionality. Any help is greatly appreciated. Thanks.
You could do this via a C/C++ plug-in, but in order for it to work in Reader it would require getting it approved by Adobe (Google "RIKLA") and I'm not entirely sure they would approve a plug-in that will not let the user exit the application until a certain field has been filled. Only way to find out is to apply though.