How to create bootstrap like popup using modelpopup extender

Hii ,

I am trying to create bootstrap like popup using my ajax modelpopup exteder in asp.net

I have tried so far as below.. Please help me to make this popup much better ..

There are few isssues with this , height , width , look and feels are not proper .

and every time if i want to add contents in my popup bidy i have to adjust heights and width

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="AddStateView.ascx.cs" Inherits="DreamTouchWebUI.controls.AddStateView" %>

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajax" %>

#	Sr.No	State Name
	<%#Container.ItemIndex+1 %>	<%#Eval("Name") %>

CancelControlID="btnClose" BackgroundCssClass="modalBackground">

State