Validate two fields on Creation Screen

[Avi Chocron]

Hi,

Do you know how can I validate that a custom field value which is entered by the user on the Issue Creation Screen won’t be the same as the Reporter field value.  

I will explain more – we’ve been asked to create a custom field on Creation Screen that called Manager. The Reporter can choose in this field a user that is defined as his Manager.

But, we need to make sure that user that is entered in the Manger custom field won't be the same as the Reporter field.

Any thoughts?

I would appreciate if there is solution for this without using any paid add-on.

Thanks in advance,

Avi