jQuery.fn.extend({
	bgSlider:function(opt){
		var src=this
		var block=false,keeper,sCSS={position:'fixed',left:0,top:0,height:'1200px',right:0,zIndex:-1,overflow:'hidden'},iCSS={position:'absolute',top:0,left:0,zIndex:-1},spinner
		dfl={
			interval:4000,
			speed:1500,
			pags:false,
			slideshow:true,
			preload:false,
			current:0,
			bgstretch:false,
			altCSS:false,
			method:'fit'
		}
		opt=$.extend(dfl,opt)
		
		if(opt.pags)opt.pags=$(opt.pags)
		if(opt.preload){
			var tmp=[]
			for(var i=0;i<this.length;i++){
				tmp[i]=new Image()
				tmp[i].src=this[i]
			}
		}
		
		spinner=$(opt.spinner)
		
		var resize=jQuery.fn.bgSlider.resize=function(){
			var im=$('#bgSlider img').eq(0),
				w=im.width(),
				l=im.css('left'),
				t='0px',
				bw=document.body.offsetWidth,
				bh=document.body.offsetHeight,
				k=im.data('width')/im.data('height')
			if(opt.method=='fit')
				if(bw/bh<k)
					im.width('auto').height(bh).css({top:t,left:l})
				else
					im.width(bw).height('auto').css({top:t,left:l})
			else
				if(!(bw/bh<k))
					im.width('auto').height(bh).css({top:t,left:l})
				else
					im.width(bw).height('auto').css({top:t,left:l})

			if(opt.method=='full')
				im.stop().animate({left:(bw-w)/2})
		}
		
		$.extend($.fn.bgSlider,{changeMethod:function(me){
			opt.method=(opt.method==me)?opt.method:me
			keeper.trigger('bgSliderRefresh')
		}})
					
		$(window).bind('resize',resize)
		
		var loadSrc=function(src){
			if(!opt.bgstretch)return loadURL(src)
			if(opt.pags)
				opt.pags.parent().eq(opt.current).addClass('current').siblings().removeClass('current')
			if(opt.slideshow)
				clearInterval(opt.slideshow),
				opt.slideshow=setInterval(function(){keeper.trigger('bgSliderNext')},opt.interval)
			var t=new Image(),lt=$('img',keeper).eq(0)
			lt.each(function(){lt=this})
			t=$(t)
			t.css(iCSS)
			if(opt.altCSS)t.css(opt.altCSS)
			keeper.append(t)
 			t.bind('load',function(){
				spinner.remove()
				var w=this.offsetWidth,
					h=this.offsetHeight,
					th=$(this)
				th.data({width:w,height:h})
				th.animate({opacity:1},opt.speed,function(){
					$(this).siblings().remove()
					block=false
					resize()
				})
				
			})
			t.css({opacity:0,left:lt.offsetLeft,width:lt.offsetWidth,height:lt.offsetHeight}).attr('src',src)
			keeper.append(spinner)
		}
	
		var loadURL=function(src){
			if(opt.pags)
				opt.pags.parent().eq(opt.current).addClass('current').siblings().removeClass('current')
			if(opt.slideshow)
				clearInterval(opt.slideshow),
				opt.slideshow=setInterval(function(){keeper.trigger('bgSliderNext')},opt.interval)
			var t=$('<div></div>').css(iCSS).css({width:'100%',height:'100%',zIndex:-1,'background-image':'url('+src+')'})
			if(opt.altCSS)t.css(opt.altCSS)
			keeper.append(t)
			t.animate({opacity:1},opt.speed,function(){
				$(this).siblings().remove()
				block=false
			})
		}
		$('body').append(keeper=$('<div id="bgSlider"></div>').css(sCSS))
		
		keeper.bind('bgSliderRefresh',function(){
			if(!block)
				block=true,
				loadSrc(src[opt.current])
		})
		
		keeper.bind('bgSliderNext',function(){
			if(!block){
				block=true
				opt.current++
				if(!(opt.current<src.length))opt.current=0
				loadSrc(src[opt.current])
			}
		})
		keeper.bind('bgSliderPrev',function(){
			if(!block){
				block=true
				if(opt.current==0)opt.current=src.length
				opt.current--
				loadSrc(src[opt.current])
			}
		})		
		if(opt.pags)$(opt.pags).live('click',function(){
			if(!block){
				block=true
				loadSrc(src[opt.current=this.rel-1])				
			}
			return false
		})
		loadSrc(src[opt.current])
		
		resize()
	}
})