Access Hidden field value in WebMethod

Hello ,

I want to access hidden field value to the server side in asp.net in webMethod.

here is my code:-

function BtnGetData() {

var rr = $("#ddlAssignUser option:selected").length;

$("#hidUsercount").val(rr);

$.ajax({

type: "POST",

contentType:"application/json; charset=utf-8",

dataType:"json",

url: "AssignTender.aspx/GetData",

data:"{}",

success:function(data){

var obj = data.d;

alert(obj);

error: function (result) {

alert("error");

}

});

}

here i am using html tag in asp.net application because of requriement...

here is my html tags:-

Now using jquery i have get the length of ddlAssignUser and store it in the Hiddenfield.

I want this HiddenField value to access on server side in WenMethod.