How to detect if the click event occurred using jQuery?

How to detect if the click event occurred using jQuery?

I have 2 buttons. I want to detect if the previous button clicked then on
2nd button click it should display some data otherwise if user is directly
clicking on the second button, it should display an alert(please click the
previous button first). I have tried to do so but not able to detect
whether the 1st button is clicked or not :-(
HTML
<input type="button" id="btn1" value="button1"></input>
<input type="button" id="btn2" value="button2"></input>
JavaScript
$('#btn1').click(function(){
alert('Button 1 Clicked');
});
$('#btn2').click(function(event) {
var inputButton = document.getElementsByTagName('input');
var $target = $(event.target);
if( $target.is(inputButton[1]) ) {
alert("Please click the 1st Button first");
} else{
alert('Button 2 Clicked');
}
});