required field validater between 7000 to 11000?

$(document).ready(function() {   
  $('.error').hide();
  $('.submit').click(function(event){
    var data=$('.infobox').val();
    var len=data.length;
    var c=0;
    var num=0;
    var flag=0;
    for(var i=0;i<len;i++)>
    {
      c=data.charAt(i).charCodeAt(0);
      if(c <48 || c >57)
      {
        $('.error').show();
        flag=1;
        event.preventDefault();
        break;
      }
      else
      {
        $('.error').hide();
      }
    }
 
    if(flag==0)
    {
      num=parseInt(data);
      if(num<7000 || num>11000)
      {
        $('.error').show();
        $('.error').text('Invalid num. Please enter the num within the range 7000 to 11000');
        event.preventDefault();
      }
    }
  });
 });

<asp:rangevalidator runat="server" type="Integer" xmlns:asp="#unknown">
MinimumValue="7000" MaximumValue="11000" ControlToValidate="TextBoxId" 
ErrorMessage="Value must be a number between 4000 and 11000" /></asp:rangevalidator>