jQuery doesn’t respond: JSFiddle?

Here is my JsFiddle link. I’m testing that jQuery works, but it doesn’t. Have I made any mistakes? I have checked documentation of jQuery and everything seems to be okay. What’s wrong?

$(document).ready(function() {
    //insert code here
    alert("this will flre when the DOM is loaded.");
});

Answer

Select the library first as given in the image below

Then you can call jQuery as below

$(document).ready(function(){
    alert("All is well");
});

Check out this live fiddle http://jsfiddle.net/mayooresan/TTu3C/