in Oracle Database 10g Express Edition and hr schema

Write PL/SQL code to create a function called total_salaries that returns the total salaries of all employees who are working in X department or working as Y job title or working in Z country name . When you call the function, you have to pass your choice parameter and the department name or job title or the country name. The function will return the total salaries of employees who are working in that given department or job title or country name