Custom Auto Number to the Document with 'Create' event.

Hi All,

I have a requirement to set the custome auto number to the document when it is created based on the values of the Page Two attributes.

I have made those Page Two attributes as required.

I have created a Pre Event for create object event type.

The issue is when i leave the Number attribute empty and click on the save button, i have getting an error saying that the number attribute cann't be empty. The code is working fine if i give some dummy number to the new document.

Is there any way to make the cutom event trigger first before the agile performs the validations.