Contains case insensitive

I have the following:

if (referrer.indexOf("Ral") == -1) { ... }

What I like to do is to make Ral case insensitive, so that it can be RAl, rAl, etc. and still match.

Is there a way to say that Ral has to be case-insensitive?

Add .toUpperCase() after referrer. This method turns the string into an upper case string. Then, use .indexOf() using RAL instead of Ral.

if (referrer.toUpperCase().indexOf("RAL") === -1) { 

The same can also be achieved using a Regular Expression (especially useful when you want to test against dynamic patterns):

if (!/Ral/i.test(referrer)) {
   //    ^i = Ignore case flag for RegExp