Creating Paydates

Creating Paydates

I am trying to create an Auto Pay date, based on Bi-Monthly dates, and have it auto fill. I want to use just Fridays and I loaded a start date, and added 14 dates to that date. It keeps coming back as a bad error on Load. Any Ideas?
//Next Pay Date Automatic
//Add auto increment number
x  =  Paydates  [ID != (1  /  7  /  2014)];
input.Next_Date = x.Next_Date + 14;
x.Next_Date = x.Next_Date + 14;