JavaScript 给表格排序

(function(){
var mTable=document.getElementById('table');
var sort=function(el,index,desc){

var mTbody=el.tBodies[0],
mRow=mTbody.rows,
len=mRow.length,
maxIndex=mRow[0].cells.length-1,
arr=[],
i;
for(i=0;i<len;i++){
arr[i]=mRow[i];
}

arr.sort(function (a,b) {
var res;
if(index>maxIndex){
return 0;
}else{
res=a.cells[index].innerHTML>b.cells[index].innerHTML;
return desc?res?-1:1:res?1:-1;
}
});

for(i=0;i<len;i++){
mTbody.appendChild(arr[i]);
}
}
sort(mTable,2);
})();