function getParameterByName(name) {
name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
var regex = new RegExp("[\\?&]" + name + "=([^]*)");
var results = regex.exec(location.search);
return results == null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
}
$preview = getParameterByName("preview");
if( $preview == "" ){
// do nothing
} else if( $preview == "control" ){
document.cookie = "lander-ab-tests-13850983=lander_control";
} else{
document.cookie = "lander-ab-tests-13850983=lander_" + $preview;
}