How to set visible row count dynamically ?

Hi,

I've a requirement to set visible row count dynamically in FPM. Initially there will be only one visible row in the list. Once Insert Row button is clicked I need to show the visible row as 2. I'm not able to find the place where can I set visible row count. The rows are getting appended but not the row count expanding to 2.

Please help.

Thanks,

JMB