An electricity company is looking at ways of getting meter readings from its customers.
It releases an application for smartphones which allows users to submit their meter reading (a 6 digit number).
When the user enters a meter reading number, the function validateReading is called.
If the number entered is a valid number between 1 and 999999 inclusive, it returns true otherwise it returns false.
isNaN(computer4) returns true
isNaN(203) returns false
Complete the function