index.txt

pragma solidity ^0.4.18;

contract Coursetro {
    
   string fName;
   uint age;
   // owner is of type address(stores address).
   address owner;

   function Coursetro(){
        owner=msg.sender;//address of the creator of contract     
   }
    
    modifier onlyOwner{
        require(msg.sender==owner);//if address of user == owner ,he/she can change the instructor else not.
        _; //runs the body of the function where the above modifier is used, if above requirement is true
    }   
       
   event Instructor(
       string name,
       uint age
    );
   
   function setInstructor(string _fName, uint _age) onlyOwner public {
       fName = _fName;
       age = _age;
       Instructor(_fName,_age); 
       
       
   }
   
   function getInstructor() public constant returns (string, uint) {
       return (fName, age);
   }
}