jQuery Issue with Smooth Slider Plugin

have the Smooth Slider plugin installed and it works on the default theme. I selected it as Display Slider on this Post/Page, and used the template tag for that specify page.php as

<?php if ( function_exists( 'get_smooth_slider' ) ) { get_smooth_slider(); } ?>

However, when I change to my custom theme with the same code it fails and gives the error message:
Uncaught TypeError: undefined is not a function for the line:
jQuery(“#smooth_slider_7”).cycle({

What should I do? I thought JQuery was already included for wordpress and I later added the code:

<?php wp_enqueue_script("jquery"); ?>
To the header