Selecting duplicates from two fields

[#1]

Hi,

I've a table with FirstName and LastName. These tables contains duplicates, because some users have registrered more than once. I need to be able to select those users, preferably with a button or through a multibox. Any ideas to how I achieve this? I have a button with two "select in field" with search string ='=count(LastName)>1' and ='=count(FirstName)>1', but this just gives me all instances in FirstName with duplicates and all instances in LastName with duplicates. I want something like "show all where count(LastName)>1' and then select all of those where count(FirstName)>1'.

Is this possible?

Thanks!

[#2]

Just after I created this post the solution came to me, I managed to solve it in the loading script:

Load

FirstName & LastName as Name

I then created a button with Select in field ='=count(Name)>1.