function dongHua1() {

	 var o=document.getElementById("bottom_nav");
	 var s=o.getElementsByTagName("li");
	 if (!o.style.left) o.style.left="0px";
     var a=parseInt(o.style.left);
	 var b=Math.abs(a);
	 var c=s.length*173;

	 if(b>=c-346){

	 return true;
	 }else{
	 if(b%173==0){gundong(a-173);}else{ return true;}
	 }
}

function dongHua2() {
	 var o=document.getElementById("bottom_nav");
	 var s=o.getElementsByTagName("li");
	 if (!o.style.left) o.style.left="0px";
     var a=parseInt(o.style.left);
	 var b=Math.abs(a);
	 var c=s.length*173;
	 if(b==0){
	 return false;
	 }else{
	  if(b%173==0){gundong(a+173);}else{ return false;}
	 }
}


function gundong(x){
          var id=document.getElementById("bottom_nav");
          if (id.yidong) {clearTimeout(id.yidong);}
          if (!id.style.left) id.style.left="0px";
          var xpos=parseInt(id.style.left);
   		  if (xpos==x) return true;
          if (xpos<x){
			  var dist=Math.ceil((x-xpos)/10);
                 xpos=xpos+dist;
			  }
          if (xpos>x){
			  var dist=Math.ceil((xpos-x)/10);
                 xpos=xpos-dist;
			  }
          id.style.left=xpos+"px";
		  var w="gundong("+x+")";
          id.yidong=setTimeout(w,10);
	    }
function biantu(href){
  var biant = document.getElementById('biant');
      biant.src = href;

}