XNA jumping with a cooldown?

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;

namespace WindowsGame3
{
    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;

        Texture2D spelare1;
        Texture2D spelare2;
        Texture2D spelare3;

        Vector2 spelare1Pos;

        bool jumping;
        float startY, jumpspeed = 0;


        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
            graphics.PreferredBackBufferWidth = 320;
            graphics.PreferredBackBufferHeight = 240;
        }

        /// <summary>
        /// Allows the game to perform any initialization it needs to before starting to run.
        /// This is where it can query for any required services and load any non-graphic
        /// related content.  Calling base.Initialize will enumerate through any components
        /// and initialize them as well.
        /// </summary>
        protected override void Initialize()
        {
            // TODO: Add your initialization logic here

            spelare1Pos = new Vector2(100, 100);
            startY = spelare1Pos.Y;
            jumping = false;
            jumpspeed = 0;

            base.Initialize();
            IsMouseVisible = true;
        }

        /// <summary>
        /// LoadContent will be called once per game and is the place to load
        /// all of your content.
        /// </summary>
        protected override void LoadContent()
        {
            // Create a new SpriteBatch, which can be used to draw textures.
            spriteBatch = new SpriteBatch(GraphicsDevice);

            spelare1 = Content.Load<Texture2D>(@"spelare1");

            // TODO: use this.Content to load your game content here
        }

        /// <summary>
        /// UnloadContent will be called once per game and is the place to unload
        /// all content.
        /// </summary>
        protected override void UnloadContent()
        {
            // TODO: Unload any non ContentManager content here
        }

        /// <summary>
        /// Allows the game to run logic such as updating the world,
        /// checking for collisions, gathering input, and playing audio.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Update(GameTime gameTime)
        {
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();


            KeyboardState keyState1 = Keyboard.GetState();
            if (keyState1.IsKeyDown(Keys.Right))
            {
                spelare1Pos.X += 1;
            }

            KeyboardState keyState2 = Keyboard.GetState();
            if (keyState2.IsKeyDown(Keys.Left))
            {
                spelare1Pos.X -= 1;
            }

            if (jumping)
            {
                spelare1Pos.Y += jumpspeed;
                jumpspeed += 1;
                if (spelare1Pos.Y >= startY)
                
                {
                    spelare1Pos.Y = startY;
                    jumping = false;
                }
            }
            else
            {
                KeyboardState keyState3 = Keyboard.GetState();
                if (keyState3.IsKeyDown(Keys.Space))
                {
                    jumping = true;
                    jumpspeed = -14;
                }
            }

            // TODO: Add your update logic here

            base.Update(gameTime);
        }

        /// <summary>
        /// This is called when the game should draw itself.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);


            spriteBatch.Begin();

            spriteBatch.Draw((spelare1), (spelare1Pos), Color.White);

            spriteBatch.End();
            // TODO: Add your drawing code here

            base.Draw(gameTime);
        }
    }
}

This is my code so far and all it pretty much does it make me able to jump and walk to side to side, now I want to have a cooldown on the jumping so I am not able to just jump as fast as I land.
Any suggestions on how I might do this?