html - jQuery image sliding up instead of sliding right -

basically code making image slide when want slide right. what's wrong it?

html

<div id="wrapper">     <div id="header">     </div> </div> 

js

var scrollspeed = 70;        // speed in milliseconds var step = 1;               // how many pixels move per step var current = 0;            // current pixel row var imageheight = 4300;     // background image height var headerheight = 300;     // how tall header is.  //the pixel row start new loop var restartposition = -(imageheight - headerheight);  function scrollbg(){  //go next pixel row. current -= step;  //if @ end of image, go top. if (current == restartposition){     current = 0; }  //set css of header. $('#header').css("background-position","0 "+current+"px");   }  //calls scrolling function repeatedly var init = setinterval("scrollbg()", scrollspeed); 

here code: http://pastebin.com/9fpvsbxm

you need increment value

function scrollbg(){      //go next pixel row.     current += step; //increment instead of decrement      //if @ end of image, go top.     if (current == restartposition){         current = 0;     }      //set css of header.     $('#header').css("background-position",current +"px 0"); // parameters right top not top right    } 

demo: fiddle