js/jquery获取文本框输入焦点的方法

 function CheckForm() {
             if(document.form1.trainingName.value==""){
                     alert("培训班名称不能为空！");
                     document.form1.trainingName.focus();
                     return false;
             }
    }

      function CheckForm() {

             var classLevel = $("#classLevel").val();
              var re = /^[1-9][0-9]*$/;
              if(!re.test(classLevel)&&classLevel.length>0){
              alert("请输年级入大于零的整数！");
              $("#classLevel").focus();
              return false;
          }
    }