JavaScript if else

In Javascript, how can I write this:

if (the referring website was http://www.mywebsite.com) {
document.write("Great, let's write some stuff here!");
}
else {
//the referrer was not appropriate so do just do nothing.
}

 

if (document.referrer == "http://www.mywebsite.com") {
  document.write("Great, let's write some stuff here!");
}
else {
  //the referrer was not appropriate so do just do nothing.
}

Code (markup):

The else part isn't needed, so you can write

if (document.referrer == "http://www.mywebsite.com") {
  document.write("Great, let's write some stuff here!");
}

Code (markup):

 

Thanks.