Checking for Null/Empty Rowset

I am having trouble checking for null empty rowset. I have some research and looked for helpful examples, but nothing I've tried seems to work.

I am trying to fill a rowset based on the oprid. I have two Fill commands. They both work fine when tested individually. However, I want to execute the first Fill command and then execute the 2nd Fill ONLY if the rowset is null or empty. I'm currently using an IF statement to try and do this. Any way to properly execute this would be appreciated.

Here is the code:

   &OPR = %OperatorId;

  

   &RS = CreateRowset(Record.CG_OC_SIGNIN);