Check if a custom properties is there and end macro if empty

Hi folks,

I’m looking for a line of code that will check to see if a specific custom property is there and if it’s not end the macro process.

I already have the macro I want set up, but just need this last line (it's actually going to be the first line) that will check to see if the field exists, if not then the macro doesnt need to run.

SolidworksApi macros