1 function getByClass(oParent,sClass){
 2     var aChild = oParent.getElementsByTagName("*"),
 3         result = [];
 4     for(var i =0;i<aChild.length;i++){
 5         if(aChild[i].className.match(new RegExp("(\\s|^)" + sClass+ "(\\s|$)"))){ //判断是否有该class
 6             result.push(aChild[i]);
 7         };
 8     };
 9     return result;
10 };