How to set the focus on the first <select> element of the page using JQuery?

Question

I would like to set the focus on the first element of the page using JQuery when the page is loaded. I could successfully set the focus for first element by using

Answer 1

You are calling on element that is not loaded in DOM. Place your code in ready function.

jQuery(document).ready(function() {
    $(":input:visible:first").focus();               
});

UPDATE:

As seen in @David answer and comments, he is right.

$(document).ready(function(){
    $("select:first").focus();
});

but you have not correctly included jquery (as seen in comment). you have missed to insert http before script src.