Creating a unique field

[Anonymous]

Hi All,

I have a field entitled "username" where people can choose their own username and our system will assign it to them

How can I make it so that this specific field doesn't allow for a duplicate username. In other words, I want the user to be informed that their username has already been chosen and that they should choose another one.

Thanks in advance!

Danish

[Anonymous]

You would need to make a call to the REST API to find out if the value of this username exists in Marketo. The relevant API is 
http://developers.marketo.com/documentation/rest/get-multiple-leads-by-filter-type/

It might be easier to do this outside of Marketo.