// JavaScript Document
/****************************************** 
 *bg AD
 ******************************************/
 /*
 *Version:       1.1.0(2009-4-16)
 *Author:        S.S.L
 *Modify:	     S.S.L(2009-5-18)
*/
function Bgad(){
	var o = this;
	var ladurl,radurl;
    var ti = 1;
	
	var adcontainer_style = {
		"id":"newbgad",
		"width":"990px",
		"margin":"0 auto",
		"position":"relative"
	}
	
	function getAdContainer(){
		var ad = document.createElement( "div" );

		ad.id= adcontainer_style.id;
		ad.style.width = adcontainer_style.width;
		ad.style.position = adcontainer_style.position;
		ad.style.margin = adcontainer_style.margin;
		
		return ad;
	}
	
	function setAdContainer( adcontainer,ad1,ad2 ){
		adcontainer.appendChild( ad1 );
		adcontainer.appendChild( ad2 );
		
		document.body.style.overflowX = "hidden";
		document.body.insertBefore( adcontainer,document.body.childNodes[0] );
	}
	
	function getAd( url,id ){
		ad = document.createElement( "div" );
		
		ad.id = id;
		
		ad.style.position = "absolute";
		ad.style.cursor = "pointer";
		ad.style.backgroundRepeat = "repeat-y";
		ad.style.backgroundAttachment = "fixed";
		
		ad.onclick = function(){
			window.open( url );
		}
		
		return ad;
	}

	//calculate position
	function resize( ad1,ad2 ){
		var adwidth,adheight,adScrollHeight,adScrollTop;
		
		if( document.all ){
			adwidth = Math.abs(document.body.clientWidth-990)/2 - 4;
			adheight = Math.min(document.body.clientHeight,document.documentElement.clientHeight);

			adScrollTop = Math.max(document.body.scrollTop,document.documentElement.scrollTop);
		} else {
			adwidth = Math.abs(document.documentElement.clientWidth-990)/2 - 4;
			adheight = document.documentElement.clientHeight;
		
			adScrollTop = document.documentElement.scrollTop;
		}
		
		if( document.compatMode != "CSS1Compat" ){
			adheight = document.body.clientHeight;
			adScrollTop = document.body.scrollTop;
		}
  		adScrollHeight = document.body.scrollHeight;
		
		/*if( adScrollHeight > ( adScrollTop + adheight ) ){
			ad1.style.top = adScrollTop + "px";
			ti = 1;
		}else if( adScrollHeight == ( adScrollTop + adheight ) ){
			if( ti == 1 )ad1.style.top = adScrollTop-5 + "px";
			ti++;
		}*/
		
		ad1.style.top = "0px";	
		ad1.style.width = adwidth + "px";
		ad1.style.height = adScrollHeight + "px";
		ad1.style.left = "-" + adwidth + "px";

		ad2.style.width = ad1.style.width;
		ad2.style.height = ad1.style.height;
		ad2.style.right = ad1.style.left;		
		ad2.style.top = ad1.style.top;
		ad1.style.backgroundPosition =Math.ceil ( adwidth-135+4 ) + "px 0";
		
		if( window.XMLHttpRequest )
			ad2.style.backgroundPosition = ad1.style.backgroundPosition;
		else
			ad2.style.backgroundPosition = "0 0";

	}
	
	this.init = function( adurl1,adurl2){
		ladurl = adurl1;
		radurl = adurl2;
		
		var adcontainer = getAdContainer();
		
		var ad1 = getAd( adurl1,"leftad" );
		var ad2 = getAd( adurl2,"rightad" );
		
		//add ad div
		setAdContainer( adcontainer,ad1,ad2 );
		
		//add listener
		if( document.all ){
			window.attachEvent( "onload",function(){resize( ad1,ad2 );} );
			window.attachEvent( "onscroll",function(){resize( ad1,ad2 );} );
			window.attachEvent( "onresize",function(){resize( ad1,ad2 );} );
		} else {
			window.addEventListener( "load",function(){resize( ad1,ad2 );},false );
			window.addEventListener( "scroll",function(){resize( ad1,ad2 );},true );
			window.addEventListener( "resize",function(){resize( ad1,ad2 );},true );
		}
	}
}