I perviously have answere similar question at Wordpess.Stackexchange
Its pretty simple.
First you have to add a function in your themes funcition.php file to register and enqueue your scripts in head using wp_enqueue_scripts hook.
// Register and enqueue all scripts in head
function custom_scripts() {
wp_register_script( 'script_to_validate', 'http://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.11.1/jquery.validate.min.js', false, false, false );
wp_enqueue_script( 'script_to_validate' );
wp_register_script( 'script_modernizr', 'http://cdnjs.cloudflare.com/ajax/libs/modernizr/2.7.1/modernizr.min.js', false, false, false );
wp_enqueue_script( 'script_modernizr' );
}
// Hook into the 'wp_enqueue_scripts' action
add_action( 'wp_enqueue_scripts', 'custom_scripts' );
Then you can call your function to initiate your script in footer using wp_footer hook as following;
// Add this in function.php as well
function call_script_in_footer(){
?>
<script>
// Add your related script over here
</script>
<?php
}
add_action( 'wp_footer', 'call_script_in_footer' );
And thats it. Now you can use this in any template you want.