(function(){

var Init = {

  start: function(){ 
    var classname = this.hasClass(document.body, 'page-sub');

    if (classname) {
      this.addEventListeners();
    }
  },

  hasClass: function (elem, className) {
    return new RegExp(' ' + className + ' ').test(' ' + elem.className + ' ');
  },

  addEventListeners: function(){
    var _this = this;
    //console.log(document.querySelectorAll('.navbar-static-top')[0]);
    window.addEventListener('resize', _this.resizeImage, false);

    this.resizeImage();
  },

  resizeImage: function(){

    var header = document.getElementById('header'),
        footer = document.getElementById('footer-wrap'),
        main = document.getElementById('main-content'),
        vp = window.innerHeight,
        bodyHeight = document.body.clientHeight,
        hHeight = header.clientHeight,
        fHeight = footer.clientHeight,
        withMinHeight = hHeight + fHeight + 830;

    if(withMinHeight >  bodyHeight ){
      var newHeight = (vp - (hHeight+fHeight)) + 'px';
      main.style.height = newHeight;
    }    
  }

};

Init.start();

})();