Revert "[JS] Declares a few variables to avoid redundancy."

This reverts commit 49f5278184c570708c00c90e0aa4c208f3fe4c17.
Revert "[JS] Removes 3 useless variables."

This reverts commit 46ccaf419249c0d39c37a2f4bf0b9bbe87b48424.
Revert "[JS] Simplifies some $(this)."

This reverts commit 281325de8576c5b5f1565a8d1a68a5d47e9dc5ff.
Revert "[JS] Simplifies using .toggle(Boolean)."

This reverts commit 20657434847a6aae5ef9350a28bcc8d3f8c69b75.