How to create checkbox and dropdownlist in webpart custom properties

using System;
using System.ComponentModel;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using Microsoft.SharePoint;
using Microsoft.SharePoint.WebControls;

namespace CustomProperties.CustomPropertiesWP
{
[ToolboxItemAttribute(false)]
public class CustomPropertiesWP : WebPart
{
public static string _value;
[System.Web.UI.WebControls.WebParts.WebBrowsable(true),
System.Web.UI.WebControls.WebParts.WebDisplayName("Enter the Value"),
System.Web.UI.WebControls.WebParts.WebDescription(""),
System.Web.UI.WebControls.WebParts.Personalizable(
System.Web.UI.WebControls.WebParts.PersonalizationScope.Shared),
System.ComponentModel.Category("anavijai Custom Properties"),
System.ComponentModel.DefaultValue("")]

public string _Value
{
get { return _value; }
set { _value = value; }
}

public Boolean _property;
[System.Web.UI.WebControls.WebParts.WebBrowsable(true),
System.Web.UI.WebControls.WebParts.WebDisplayName("Check box property"),
System.Web.UI.WebControls.WebParts.WebDescription(""),
System.Web.UI.WebControls.WebParts.Personalizable(
System.Web.UI.WebControls.WebParts.PersonalizationScope.Shared),
System.ComponentModel.Category("anavijai Custom Properties"),
System.ComponentModel.DefaultValue("")]

public Boolean _Property
{
get { return _property; }
set { _property = value; }
}

public enum siteLists { List1, List2, List3 };
protected siteLists _list;
[System.Web.UI.WebControls.WebParts.WebBrowsable(true),
System.Web.UI.WebControls.WebParts.WebDisplayName("Select the List"),
System.Web.UI.WebControls.WebParts.WebDescription(""),
System.Web.UI.WebControls.WebParts.Personalizable(
System.Web.UI.WebControls.WebParts.PersonalizationScope.Shared),
System.ComponentModel.Category("anavijai Custom Properties"),
System.ComponentModel.DefaultValue("")]

public siteLists _List
{
get { return _list; }
set { _list = value; }
}

protected override void CreateChildControls()
{
Label lblMessage = new Label();
lblMessage.Text = "Custom Properties";
this.Controls.Add(lblMessage);
}
}
}