jquery click事件反复累加绑定

<div id="moveTree" onclick="treeLeft()">左移</div>

jquery click事件会重复累加绑定

??? function treeLeft(){
??? ??? alert("one");

?????? if($("#moveTree").attr("onClick")!=undefined)
??? ??? $("#moveTree").attr("onclick",'');
??? ??? $("#moveTree").click(function(){
??? ??? ??? treeRight();
??? ??? });
??? }
??? //目录居右
??? function treeRight(){
??? ??? alert("two");
??? ??? $("#moveTree").click(function(){
??? ??? ??? treeLeft();
??? ??? });
???
??? }

//连续单击“左移”，每次弹出了one、two会越来越多

应该在绑定新事件前，解除已有绑定

$("#moveTree").unbind("click");