Hello everyone, 

I have an Element Parameter PredecessorOperations(i_operation) that holds the value of the operation that has to be executed before i_operation. With the following statement i want to check if the EP has a value or not: 

if (val(PredeccesorOperation(i_operation)) = 0) then

….

endif;

However this only works if all values of the Ep are empty. If any operation gets assigned a predeccesor (e.g. Operation1) then i get the error: Cannot compute the value of string “Operation1”. 

If I would casually formulate the code it would look like this:

if( PredeccesorOperation(i_operation) is empty ) then 

….

endif;

So my question is: What operator do I need to use in order to check if the parameter has any value or no value assigned?

I am thankful for any advice you might have.

With kind regards

Andrew