i try to setup a Duplicate record warning when user input data in a form.

I have three fields :

"Item référence" : a no duplicate filed

"Start date" : date of use of the item

"End date" : date of end of use of the item.

If I select for a second record a period inside the period allready selected for the same item, an alert prevent me of saving the record.

Exemple :

Row 1 Item1 - 01/01/2015 - 31/01/2015 : input accepted

Row 2 Item1 - 01/02/2015 - 28/02/2015 : Input accepted

Row 3 Item1 - 27/02/2015 - 31/03/2015  : Alert " period is already used for this item ! " 

(for the 27th of feb is already inside Row2's period)

Is there any way to program that in Deluge Script ?

Best regards

V