js 获得多个checkbox的值

function test(){
		 if(confirm('你确定要删除吗')){

			 var obj = document.getElementsByName("check");
			 var str="";
			 var check_val = [];
			 for(var i=0;i<obj.length;i++){
			        if(obj[i].checked)
			            check_val.push(obj[i].value);
 //拼接所有的id
			       		 str+="sno="+obj[i].value+"&";
			    }
			    str=str.substring(0, str.length-1);
			   location.href="${pageContext.request.contextPath }/RemoveMuchServlet?"+str;;
			   
			}
	 }

 <a class="btn btn-default" href="javascript:void(0);" role="button" onclick="test()">删除</a>