How to update useraccount with username validation „if record exists“

Hi,

i have a problem with a Serverconnect Update Form and the correct validation setting for username.

My userupdate form needs the ability to change username and password.

How do I correctly create a form to update a username? I have the validation „if record exists in database“. My problem is the validation of the username if there is no change of the username.

I get a validation message that the username already exists. What i need to know is how to set the condition if there is no change, not to validate.

Thanks a lot for your help in advance.

Marcel