Can't achieve jumping in Javascript Game -

i developing javascript game (almost based on tutorial yet, not worried of sharing code).

the problem is, can't character jump after pressing space button. please, can @ code , me?

// edit: sorry lack of information provided. thing - code written, game in state, character animated (=is running) , backgrounds moving. yesterday, tried implement basic controls, such jump pressing spacebar. thing is, player won't jump @ all, , browser console not giving me error statements.

character defined player on line 5. , 321. in code provided below.

the jumping defined in following examples:

pressing space button

    var key_codes = {     32: 'space'   };   var key_status = {};   (var code in key_codes) {     if (key_codes.hasownproperty(code)) {        key_status[key_codes[code]] = false;     }   }   document.onkeydown = function(e) {     var keycode = (e.keycode) ? e.keycode : e.charcode;     if (key_codes[keycode]) {       e.preventdefault();       key_status[key_codes[keycode]] = true;     }   };   document.onkeyup = function(e) {     var keycode = (e.keycode) ? e.keycode : e.charcode;     if (key_codes[keycode]) {       e.preventdefault();       key_status[key_codes[keycode]] = false;     }   }; 

other jump information (please, read comments in code)

this.update = function() {        // jump, if characted not jumping or falling       if (key_status.space && this.dy === 0 && !this.isjumping) {         this.isjumping = true;         this.dy = this.jumpdy;         jumpcounter = 12;         assetloader.sounds.jump.play();       }        // longer jump if space bar pressed down longer       if (key_status.space && jumpcounter) {         this.dy = this.jumpdy;       }        jumpcounter = math.max(jumpcounter-1, 0);        this.advance();        // gravity       if (this.isfalling || this.isjumping) {         this.dy += this.gravity;       }        // change animation is-falling       if (this.dy > 0) {         this.anim = this.fallanim;       }       // change animation is-jumping       else if (this.dy < 0) {         this.anim = this.jumpanim;       }       else {         this.anim = this.walkanim;       }        this.anim.update();     };         /**      * update sprite's position player's speed      */     this.update = function() {       this.dx = -player.speed;       this.advance();     };     /**      * draw current player's frame      */     this.draw = function() {       this.anim.draw(this.x, this.y);     };   }   player.prototype = object.create(vector.prototype); 

everything seems fine me, player won't move. :(

any help?

if curious full code, go here: http://pastebin.com/dhzkhbmt

edit2:

thank replies far.

i have moved requestanimframe end of function - keep in mind, thanks.

i have implemented simple jumping script ashish provided above, character still not jumping.

this looks now:

/** jump keys definition **/      $(document).keypress(function(e){          if(e.which==32){              $('player.prototype').css({'top':"0px"});          }      settimeout(function(){          $('player.prototype').css({'top':"200px"});     },350);      });  /** defining character **/      function player(x, y) {         this.dy        = 0;         this.gravity   = 1;         this.speed     = 6;         this.jumpdy    = -10;         this.isjumping = false;         this.width     = 60;         this.height    = 96;         this.sheet     = new spritesheet('imgs/normal_walk.png', this.width, this.height);         this.walkanim  = new animation(this.sheet, 4, 0, 11);         this.jumpanim  = new animation(this.sheet, 4, 3, 3);         this.fallanim  = new animation(this.sheet, 4, 3, 3);         this.anim      = this.walkanim;         vector.call(this, x, y, 0, this.dy);          var jumpcounter = 0;  // maximalna dlzka drzania tlacidla skakania       }       player.prototype = object.create(vector.prototype); 

where wrong?

i've tried in http://jsfiddle.net/ykge9/1/

and have infinite loop in animate, requestanimframe should @ end of function:

 /**   * loop cykly hry   */   function animate() {      background.draw();      (i = 0; < ground.length; i++) {       ground[i].x -= player.speed;       ctx.drawimage(assetloader.imgs.grass, ground[i].x, ground[i].y+250);     }      if (ground[0].x <= -platformwidth) {       ground.shift();       ground.push({'x': ground[ground.length-1].x + platformwidth, 'y': platformheight});     }      player.anim.update();     player.anim.draw(64, 260);     requestanimframe( animate );   }