Please help me to find simple mathod to get  working hours

ardate is date argument  in afunction
id would be integer argument

Choose  case  dayname(ardate)   case  'monday' select mon_hrs into:l_db_hrs from workhrs where empid= :id;     case  'tuesday' select tue_hrs into:l_db_hrs from workhrs where empid= = :id;     case  'wednesday' Go to the complete details ...