function doResize(){

  var myWidth = 0, myHeight = 0;
  if( typeof( window.innerWidth ) == 'number' ) {
    //Non-IE
    myWidth = window.innerWidth;
    myHeight = window.innerHeight;
  } else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
    //IE 6+ in 'standards compliant mode'
    myWidth = document.documentElement.clientWidth;
    myHeight = document.documentElement.clientHeight;
  } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
    //IE 4 compatible
    myWidth = document.body.clientWidth;
    myHeight = document.body.clientHeight;
  }
  //window.alert( 'Width = ' + myWidth );

  if(myWidth > 1680){
    document.body.style.backgroundImage = "url(gfx/bg_body_1920.jpg)";
  }
  else if(myWidth > 1366 && myWidth <= 1680){
    document.body.style.backgroundImage = "url(gfx/bg_body_1680.jpg)";
  }
  else if(myWidth > 1280 && myWidth <= 1366){
    document.body.style.backgroundImage = "url(gfx/bg_body_1366.jpg)";
  }
  else if(myWidth > 1024 && myWidth <= 1280){
    document.body.style.backgroundImage = "url(gfx/bg_body_1280.jpg)";
  }
  else{
    document.body.style.backgroundImage = "url(gfx/bg_body_1024.jpg)";
  }
  document.body.style.backgroundRepeat = 'NO-REPEAT';
  document.body.style.backgroundPosition = 'top left';

}