How to convert this certain jQuery function into JavaScript

jQuery(document).ready(function(){

    // INT
    // the height of the highest one
    var highestlanguage = 0;

    // get highest language so it will not scroll up.
    var _gethighestlanguage = function () {
        var _height = jQuery(this).height();
        if(highestlanguage<_height) {
            highestlanguage = _height;
        }
    };

    // It's not a "real toggle". Just close all and slide down the one
    var _togglelanguage = function(){
        var _target = jQuery(this).data('target');
        jQuery(".language").hide();
        jQuery("#"+_target).slideDown();
    };

    // close the nearest element with the class "language". So don't use it in these boxes again
    var _closelanguage = function () {
        jQuery(this).closest('.language').slideUp();
    };

    // Get highest language
    jQuery(".language").each(_gethighestlanguage);

    // Assign height to the container. (Prevents page from up-scrolling on close)
    jQuery(".container").css("min-height", highestlanguage + "px");

    // Hide All
    jQuery(".language").hide();

    // Assign functions to the buttons
    jQuery('.toggle').click(_togglelanguage);
    jQuery(".close").click(_closelanguage);
});