I'm trying to create a customize default value input on my NewForm.aspx.
It's based on counting the number of entries so far (including 0) and then taking that value, add with some text ("RT-1" for example) and have it the default value for the next entry, so it will be incremental. Also, I'll have to create a condition that, if there are no items in a list that it starts at 0 count. Is this possible? Here's what I wrote so far but nothings working: