焦点图片轮换js代码

function $(id) { return document.getelementbyid(id); }

function addloadevent(func){
 var oldonload = window.onload;
 if (typeof window.onload != 'function') {
  window.onload = func;
 } else {
  window.onload = function(){
   oldonload();
   func();
  }
 }
}

function addbtn() {
 if(!$('focus_turn')||!$('focus_pic')||!$('focus_tx')) return;
 var focuslist = $('focus_pic').getelementsbytagname('li');
 if(!focuslist||focuslist.length==0) return;
 var btnbox = document.createelement('div');
 btnbox.setattribute('id','focus_btn');
 var spanbox ='';
 for(var i=1; i<=focuslist.length; i++ ) {
  var spanlist = ''+i+'';
  spanbox += spanlist;
 }
 btnbox.innerhtml = spanbox;
 $('focus_turn').appendchild(btnbox);
 $('focus_btn').getelementsbytagname('span')[0].classname = 'current';
}

var autokey = false;
function btnturn() {
 if(!$('focus_turn')||!$('focus_pic')||!$('focus_tx') || !$('focus_btn')) return;
 $('focus_turn').onmouseo教程ver = function(){autokey = true};
 $('focus_turn').onmouseout = function(){autokey = false}; 
 var focuslist = $('focus_pic').getelementsbytagname('li');
 var btnlist = $('focus_btn').getelementsbytagname('span');
 var txlist = $('focus_tx').getelementsbytagname('li');
 for (var m=0; m   btnlist[m].onmouseover = function() {
   classnormal();
   this.classname='current';
   var n=this.childnodes[0].nodevalue-1;
   focuslist[n].classname='current';
   txlist[n].classname='current';
  }
 }
}

addloadevent(addbtn);
addloadevent(btnturn);
addloadevent(setautoturn);

function setautoturn() {
 setinterval('autoturn()', 5000);
}

function autoturn() {
 if(!$('focus_turn')||!$('focus_pic')||!$('focus_tx')) return;
 if (autokey) return;
 var focuslist = $('focus_pic').getelementsbytagname('li');
 var btnlist = $('focus_btn').getelementsbytagname('span');
 var txlist = $('focus_tx').getelementsbytagname('li');
 for(var i=0; i   if (focuslist[i].classname == 'current') {
   var currentnum = i;
  }
 }
 if (currentnum==focuslist.length-1 ){
  classnormal();
  classcurrent(0);
 } else {
  classnormal();
  classcurrent(currentnum+1);
 }

}

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