How to do if(var1==var2){………} in js? [on hold]

How to make such statements in js?

<?php
    if($var=='$var2'){……}
?>

Ive already tried

if(btn9==x&&btn8==x&&btn7==x){
    msg.html("win");
}else{
    msg.html("");
}

but didn't work

Anyway Thanks in advance.