gistfile1.js

function MyClass()
{
    
    var self = this 

    // warning message if mouse moves more than halfway across the screen
    this.check_mouse = function() {
        if (mouse_x >= SCREEN_WIDTH / 2)
        {
            alert("What are you doing?!");
        }
    };
 
    setInterval(function(){
       self.check_mouse()
    }, 5000);
}
 
var MyInstance = new MyClass();
 
// Will I need to instead use setInterval("MyInstance.check_mouse()", 5000) if I want to call that instance's check_mouse() each time?