I want to add functionality in a custom button to convert a pending agreement into an agreement.

Both Pending Agreement and Agreement objects are custom objects.

So when viewing a Pending Agreement and the convert to agreement button is clicked, then a check will be performed to see if an agreement already exists, if it does then edit the record otherwise create a new record.

How would I go about creating this functionality?

I want to add functionality in a custom button to convert a pending agreement into an agreement.

Both Pending Agreement and Agreement objects are custom objects.

So when viewing a Pending Agreement and the convert to agreement button is clicked, then a check will be performed to see if an agreement already exists, if it does then edit the record otherwise create a new record.

How would I go about creating this functionality?