I am not a developer, but I am trying to figure out how to create a button and I've been sent here from the success forum. I have a button that will clone an existing record based on a stored record ID. It works fine, however, if that previous record field is blank (one doesn't exist yet) it errors out in a not very nice way.  What I want to do is any of the following:
1) Disable the button if there is no previous record (stored in the field Account.LastExam_ID__c)
2) Create a cloned record if an ID exists or create a new record if one does not exist
3) If a record does not exist, at least give a nice error message and return them to the original page.

The url (which works) to create a clone is this:
/{!Account_LastExam_ID__c}/e?clone=1&CF00N54000000Px0Y={!Treatment__c.Name}&CF00N54000000Px0Y_lkid={!Treatment__c.Id}&retURL=%2F{!Treatment__c.Id}&RecordType={!IF( Treatment__c.ADA_Code__c ="191", "012540000004Nma", "012540000004NmV")}

The url (which works) to create a new record is this:

/a5U/e?CF00N54000000Px0Y={!Treatment__c.Name}&CF00N54000000Px0Y_lkid={!Treatment__c.Id}&retURL=%2F{!Treatment__c.Id}&RecordType={!IF( Treatment__c.ADA_Code__c ="191", "012540000004Nma", "012540000004NmV")}

I thougth I could make it work by creating a variable that held either "a5U" or the value of "Account_LastExam__c" and another one that held either a blank or "clone=1&" and inserting them into the code like this:
/{!Treatment__c.Clone_button_URL__c}/e?{!Treatment__c.Clone_button_URL_2__c}&CF00N54000000Px0Y={!Treatment__c.Name}&CF00N54000000Px0Y_lkid={!Treatment__c.Id}&retURL=%2F{!Treatment__c.Id}&RecordType={!IF( Treatment__c.ADA_Code__c ="191", "012540000004Nma", "012540000004NmV")}

But it doesn't work. The "clone=1&" doesn't come over correctly. It almost works. But it doesn't work. Any suggestions would be very welcome.