SOURCE

var performanceS = function(salary){
			return salary * 4;
		}

		var performanceA = function(salary){
			return salary * 3;
		}

		var performanceB = function(salary){
			return salary * 2;
		}

		var calculateBonus = function(performanceLevel,salary){
			if(performanceLevel === 'S'){
				return performanceS(salary)
			}

			if(performanceLevel === 'A'){
				return performanceA(salary)
			}

			if(performanceLevel === 'B'){
				return performanceB(salary)
			}
		}

		console.log(calculateBonus('A',10000))