JavaScript Arithmetic Operators Syntax

I am using Captivate 9 and executing a JavaScript from within an advanced action.

What is the correct syntax for comparing two variables in a conditional statement?

e.g To check equality I have successfully used the syntax..... if(x == y){

                                                                                                   var z = 1;

                                                                                                }

however when I try to check for the arithmetic operator ...."is less than", Captivate 9 will not allow me to  "update" the script....

e.g.           I tried.....      if(x < y){

                                        var z = y;

                                     }

I know that an advanced action script does not offer a "<" arithmetic operator Does that mean that  javascript that is executed within an advanced action, also will not allow the "is less than" arithmetic operation??

Thank you for your assistance.