c# - XNA - Make sprite unable to go out of borders -

i've been playing little around minx , miny, can't make work. have player( box ), use mouse guide around. can cross borders player can't seen. fix that, can't figure out how.

heres code ( give complete, since not sure part of need):

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 squaregame {     /// <summary>     /// main type game     /// </summary>     public class game1 : microsoft.xna.framework.game     {         graphicsdevicemanager graphics;         spritebatch spritebatch;          public game1()         {             graphics = new graphicsdevicemanager(this);             content.rootdirectory = "content";         }          /// <summary>         /// allows game perform initialization needs before starting run.         /// can query required services , load non-graphic         /// related content.  calling base.initialize enumerate through components         /// , initialize them well.         /// </summary>         protected override void initialize()         {             // todo: add initialization logic here              base.initialize();         }          /// <summary>         /// loadcontent called once per game , place load         /// of content.         /// </summary>         ///            texture2d player;         vector2 spriteposition = vector2.zero;         private vector2 origin;         private vector2 screenpos;         protected override void loadcontent()         {             // create new spritebatch, can used draw textures.             spritebatch = new spritebatch(graphicsdevice);             player = content.load<texture2d>("models\\player");             viewport viewport = graphics.graphicsdevice.viewport;             origin.x = player.width / 2;             origin.y = player.height / 2;             screenpos.x = viewport.width / 2;             screenpos.y = viewport.height / 2;                // todo: use this.content load game content here         }          /// <summary>         /// unloadcontent called once per game , place unload         /// content.         /// </summary>         protected override void unloadcontent()         {             // todo: unload non contentmanager content here         }          /// <summary>         /// allows game run logic such updating world,         /// checking collisions, gathering input, , playing audio.         /// </summary>         /// <param name="gametime">provides snapshot of timing values.</param>         private float rotationangle;         protected override void update(gametime gametime)         {             // allows game exit             if (gamepad.getstate(playerindex.one).buttons.back == buttonstate.pressed)                 this.exit();              float elapsed = (float)gametime.elapsedgametime.totalseconds * 2;              // todo: add update logic here              rotationangle += elapsed;             float circle = mathhelper.pi * 2;             rotationangle = rotationangle % circle;;              spriteposition.x = mouse.getstate().x;             spriteposition.y = mouse.getstate().y;              base.update(gametime);         }          /// <summary>         /// called when game should draw itself.         /// </summary>         /// <param name="gametime">provides snapshot of timing values.</param>         ///          protected override void draw(gametime gametime)         {             graphics.graphicsdevice.clear(color.lightgoldenrodyellow);              // todo: add drawing code here             spritebatch.begin();             spritebatch.draw(player, spriteposition, null, color.white, rotationangle, origin, 1.0f, spriteeffects.none, 0f);             spritebatch.end();               base.draw(gametime);         }     } } 

and picture of player @ border: http://imgur.com/7dnlag3

thank in advance! :)

in update method say:

if(mouse.getstate().x > 0 && mouse.getstate().x < yourwindowwidth)                 spriteposition.x = mouse.getstate().x; else if (mouse.getstate().x < 0)     spriteposition.x = 0; else                   //the mouse out right side of window.     spriteposition.x = yourwindowwidth; if(mouse.getstate().y > 0 && mouse.getstate().y < yourwindowheight)     spriteposition.y = mouse.getstate().y; else if (mouse.getstate().y < 0)     spriteposition.y = 0; else                   //the mouse out bottom side of window.     spriteposition.y = yourwindowheight; 

hope helps.