cloudsMainIntervalTime = 42000;
cloudsTopIntervalTime = 26000;

$(function () {
setInterval("scrollCloudsMainBackground( )", cloudsMainIntervalTime); 
setInterval("scrollCloudsTopBackground( )", cloudsTopIntervalTime); 
  $("#cloudBackground").css( 'background-position', '0px 0px' );
  $("#cloudBackgroundTop").css( 'background-position', '0px 0px' );
  scrollCloudsMainBackground();
  scrollCloudsTopBackground();
});

function scrollCloudsMainBackground( ) {
  var currentCloudBackgroundPosition = $("#cloudBackground").css( 'background-position' ).split(' ')[0].replace('px','');
  var newBackgroundPosition = ( currentCloudBackgroundPosition - 1024 ) + "px 0";
  $("#cloudBackground").animate({ 'background-position': newBackgroundPosition }, cloudsMainIntervalTime, 'linear' );
}

function scrollCloudsTopBackground( ) {
  var currentCloudBackgroundPosition = $("#cloudBackgroundTop").css( 'background-position' ).split(' ')[0].replace('px','');
  var newBackgroundPosition = ( currentCloudBackgroundPosition - 1024 ) + "px 0";
  $("#cloudBackgroundTop").animate({ 'background-position': newBackgroundPosition }, cloudsTopIntervalTime, 'linear' );
}