Having problem with the condition based on in salary rule when creating payroll my problem is that if i write any condition in the (condition based on section) this condition must be achieved otherwise the rule won't work and give me an error like for example.

To calculate the sick days for employees to shown in their pay slips  wrote this code in the COMPUTATION  panel and it work very fine only if the employee have sick leave but it won't work with the employee who don't have sick days it gives error. 

the code is:

result = worked_days['LEAVE110'] and worked_days['LEAVE110'].number_of_days

the problem comes from the condition panel i can't choose (always true) as i want to calculate this only if the employee have sick leave other wise i don't want to calculate this rule

would you plz help me with condition base on panel 

what should i write?