function preloader() 
{
     // counter
     var i = 0;
     // create object
     imageObj = new Image();
     // set image list
     images = new Array();
     images[0]="images/bg_topnav_selected.gif"
     images[1]="images/bg_topnav_corner_l.gif"
     images[2]="images/bg_home_btn.gif"
     images[3]="images/bg_topnav_corner_rt.gif"
     // start preloading
     for(i=0; i<=3; i++) 
     {
          imageObj.src=images[i];
     }
}