if else statement2 problem in jquery

if else statement2 problem in jquery

<!DOCTYPE html>
<html>
<head>
<script>
$(document).ready(function() 
{
 $('#year').blur(function()
  {
    var yearRegExp = /^[0-9]+$/;
          var v_year=$("#year").val();
         
          if (v_year=="") //not working in o/p
           {
             $("#year").css({"border":"1px solid red"});
             $("#year_error").text("you can't Leave This Empty!");
             $("#year_error").css({"margin-top":"5px"});
          } 

          else if (!yearRegExp.test(v_year)) //not working in o/p
          {
           $("#year").css({"border":"1px solid red"});
            $("#year_error").text("Please Enter Numeric Values Only");
            $("#year_error").css({"margin-top":"5px"});
          }

          else if (v_year.length != 4) //not working in o/p
          {
           $("#year").css({"border":"1px solid red"});
            $("#year_error").text("Year is not proper. Please check");
            $("#year_error").css({"margin-top":"5px"});
           }

           var current_year=new Date().getFullYear();
           if ((v_year < 1920) || (v_year > current_year)) / not /working in o/p         
          {
           $("#year").css({"border":"1px solid red"});
            $("#year_error").text("Year should be in range 1929 to current year");
            $("#year_error").css({"margin-top":"5px"});
           }          }
          else 
          {
            $("#year").css({"border":"1px solid grey"});
             $("#year_error").text("");
             $("#year_error").css({"margin-top":"0px"});
            return false;
          }
  });


});
</script>
</head>
<body>
<div id="wrapper">
<form id="eg" action="/">
<div id = "form_name">
<div>
 <label class="label">Year</label></div>
<input type="text" name="year" id="year" class="input_year" placeholder="Year" maxlength="4" required>
 <span class='error_text' id='year_error'></span>
</div>
</div>
</form>
</div>

</body>
</html>

i need each statement will execute on browser 
if u have tried solved this problem 
thank u in advanced.............