I am validating form using jquery validation plugin......

 rules: {
    Name: "required",
    MobileNo: {
           required: true,
           minlength: 10, remote: '<%=Url.Action("getClientMobNo", "Clients") %>'
               },
    Address: "required"
            },
    messages: {
        Name: "please provide a client name",
        MobileNo: {
        required: "Please provide a mobile phone no",
        rangelength: jQuery.format("Enter at least {0} characters"),
        remote: jQuery.format("This MobileNo is already in use")
      },
      Address: "please provide client address"
   },

This works pretty well on add form validation but i use the same form for edit here they can use the same mobile no,but my plugin validates that mobileno saying there is already a mobileno... But how to execute remote attribute based on a condition,

   MobileNo: {
           required: true,
           minlength: 10,
          if($("#HfId").val() == ""){ 
            remote: '<%=Url.Action("getClientMobNo", "Clients") %>'
             }
          },

Is this a valid jquery conditional validation statement.... How to skip remote attribute based on a condition....