var TAF = {
  overlay : null,
  box : null,
  boxContents : null, 

  showBox : function(href, boxWidth, boxHeight) {
    this.setDimensions(boxWidth, boxHeight);
    this.boxContents.innerHTML = '<iframe src="'+href+'"></iframe>';
    this.overlay.style.display = 'block';
    this.center();
    return false;
  },
  
  setDimensions : function(width, height) {
    var windowSize = this.getPageDimensions();
    if(width) {
      if(width < windowSize[0]) {
        this.box.style.width = width + 'px';
      } else {
        this.box.style.width = (windowSize[0] - 50) + 'px';
      }
    }
    if(height) {
      if(height < windowSize[1]) {
        this.box.style.height = height + 'px';
      } else {
        this.box.style.height = (windowSize[1] - 50) + 'px';
      }
    }
  },
  
  
  hideBox : function(){
    this.boxContents.innerHTML = '';
    this.box.style.width = null;
    this.box.style.height = null;
    this.overlay.style.display = 'none';
    this.box.style.display = 'none';
    return false;
  },
  
  // taken from lightbox js, modified argument return order
  getPageDimensions : function(){
    var xScroll, yScroll;
  
    if (window.innerHeight && window.scrollMaxY) {  
      xScroll = document.body.scrollWidth;
      yScroll = window.innerHeight + window.scrollMaxY;
    } else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
      xScroll = document.body.scrollWidth;
      yScroll = document.body.scrollHeight;
    } else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
      xScroll = document.body.offsetWidth;
      yScroll = document.body.offsetHeight;
    }
    
    var windowWidth, windowHeight;
    if (self.innerHeight) {  // all except Explorer
      windowWidth = self.innerWidth;
      windowHeight = self.innerHeight;
    } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
      windowWidth = document.documentElement.clientWidth;
      windowHeight = document.documentElement.clientHeight;
    } else if (document.body) { // other Explorers
      windowWidth = document.body.clientWidth;
      windowHeight = document.body.clientHeight;
    }  
    
    // for small pages with total height less then height of the viewport
    if(yScroll < windowHeight){
      pageHeight = windowHeight;
    } else { 
      pageHeight = yScroll;
    }
  
    // for small pages with total width less then width of the viewport
    if(xScroll < windowWidth){  
      pageWidth = windowWidth;
    } else {
      pageWidth = xScroll;
    }
    arrayPageSize = new Array(windowWidth,windowHeight,pageWidth,pageHeight) 
    return arrayPageSize;
  },
  
  center : function(){
    try{
      element = this.box;
    }catch(e){
      return;
    }
    var windowSize = this.getPageDimensions();
    var window_width  = windowSize[0];
    var window_height = windowSize[1];
    
    this.overlay.style.height = windowSize[3] + 'px';
    
    element.style.position = 'absolute';
    element.style.zIndex   = 99;
  
    var scrollY = 0;
  
    if ( document.documentElement && document.documentElement.scrollTop ){
      scrollY = document.documentElement.scrollTop;
    }else if ( document.body && document.body.scrollTop ){
      scrollY = document.body.scrollTop;
    }else if ( window.pageYOffset ){
      scrollY = window.pageYOffset;
    }else if ( window.scrollY ){
      scrollY = window.scrollY;
    }

    element.style.display = 'block';
    var setX = ( window_width  - element.offsetWidth  ) / 2;
    var setY = ( window_height - element.offsetHeight ) / 2 + scrollY;
  
    setX = ( setX < 0 ) ? 0 : setX;
    setY = ( setY < 0 ) ? 0 : setY;
  
    element.style.left = setX + "px";
    element.style.top  = setY + "px";
    
  },
  
  init : function() {       
    this.overlay = document.getElementById('overlay');
    this.box = document.getElementById('box');
    this.boxContents = document.getElementById('boxContents');
  }
}