Compare two number using JavaScipt (Amateur question)

I want to compare two number of using JavaScipt and find a bigger number. Specifically, I have the following two numbers:

adjustY-100
40

I want to compare these two and find a bigger number. Is there a function to do this ...? Or I need to use an operator to find the bigger number?

 

You would need to actually have 2 input field and and a button to compare
and then replace the values with their element names
ex.
x = document.form1.name1.value
y = document.form1.name2.value

and the button would be there to activate the function

function compare() {

var x=100
var y=40

if ( x > y ){
document.write("x is the bigger number");
}
else{
document.write("y is the bigger number");
}
}

 

Function should be:
function compare() {

var x=100;
var y=40;

if ( x > y ){
document.write("x is the bigger number");
}
else{
if(x==y){
document.write("y is equal to x");
}else{
document.write("y is the bigger number");
}

}
}

 

If you only need the larger of the two values you can do it like this:

biggest = Math.max(AdjustY - 100, 40);

Code (markup):