I have already posted and provided the required PLSQL Library and the Calendar FMX file in my previous blog post Date Picker Calendar For Oracle Forms but some people were still not able to use this utility in their forms, so I thought to provide a demo form by using Calendar form utility into it.
I have attached the packages in Program Unit of this demo form, now no need to attached that library to this form, you can use it directly but if you want to use it in all of your forms then I will recommend to attache the library, which I am providing also in source code.
Note: File general.plx and Foxcal.fmx should be in the directory from where you are running the demo form or your form which you will develop.
