How can i call from external js file

I have a javascript file that contains the following objects and functions ........

;( function( window ) {

    'use strict';

    function extend( a, b ) {
        for( var key in b ) { 
            if( b.hasOwnProperty( key ) ) {
                a[key] = b[key];
            }
        }
        return a;
    }

    // taken from https://github.com/inuyaksa/jquery.nicescroll/blob/master/jquery.nicescroll.js
    function hasParent( e, id ) {
        if (!e) return false;
        var el = e.target||e.srcElement||e||false;
        while (el && el.id != id) {
            el = el.parentNode||false;
        }
        return (el!==false);
    }

    // returns the depth of the element "e" relative to element with id=id
    // for this calculation only parents with classname = waypoint are considered
    function getLevelDepth( e, id, waypoint, cnt ) {
        cnt = cnt || 0;
        if ( e.id.indexOf( id ) >= 0 ) return cnt;
        if( classie.has( e, waypoint ) ) {
            ++cnt;
        }
        return e.parentNode && getLevelDepth( e.parentNode, id, waypoint, cnt );
    }


    // returns the closest element to 'e' that has class "classname"
    function closest( e, classname ) {
        if( classie.has( e, classname ) ) {
            return e;
        }
        return e.parentNode && closest( e.parentNode, classname );
    }

function mlPushMenu( el, trigger, options ) {   
        this.el = el;
        this.trigger = trigger;
        this.options = extend( this.defaults, options );
        // support 3d transforms
        this.support = Modernizr.csstransforms3d;
        if( this.support ) {
            this._init();
        }
    }

    mlPushMenu.prototype = {
        defaults : {
            // overlap: there will be a gap between open levels
            // cover: the open levels will be on top of any previous open level
            type : 'overlap', // overlap || cover
            // space between each overlaped level
            levelSpacing : 40,
            // classname for the element (if any) that when clicked closes the current level
            backClass : 'mp-back'
        },
        _init : function() {
            // if menu is open or not
            this.open = false;
            // level depth
            this.level = 0;
            // the moving wrapper
            this.wrapper = document.getElementById( 'mp-pusher' );
            // the mp-level elements
            this.levels = Array.prototype.slice.call( this.el.querySelectorAll( 'div.mp-level' ) );
            // save the depth of each of these mp-level elements
            var self = this;
            this.levels.forEach( function( el, i ) { el.setAttribute( 'data-level', getLevelDepth( el, self.el.id, 'mp-level' ) ); } );
            // the menu items
            this.menuItems = Array.prototype.slice.call( this.el.querySelectorAll( 'li' ) );
            // if type == "cover" these will serve as hooks to move back to the previous level
            this.levelBack = Array.prototype.slice.call( this.el.querySelectorAll( '.' + this.options.backClass ) );
            // event type (if mobile use touch events)
            this.eventtype = mobilecheck() ? 'touchstart' : 'click';
            // add the class mp-overlap or mp-cover to the main element depending on options.type
            classie.add( this.el, 'mp-' + this.options.type );
            // initialize / bind the necessary events
            this._initEvents();
        },

        // close the menu
        _resetMenu : function() {
            this._setTransform('translate3d(0,0,0)');
            this.level = 0;
            // remove class mp-pushed from main wrapper
            classie.remove( this.wrapper, 'mp-pushed' );
            this._toggleLevels();
            this.open = false;
        },



// add to global namespace
    window.mlPushMenu = mlPushMenu;

} )( window );

      

        
        
        
      

    

I have a question how to call the _resetMenu object in another script. to my bad knowledge it must be ......

window.mlPushMenu._resetMenu(); 

      

        
        
        
      

    

which should execute this object in my mind, but it doesn't work that cleanly, I'm wrong ... Any help here would be much appreciated.

this is an example of the button I have created so far.

$('.iconM-referrals').on('click', function () {
      window.mlPushMenu._resetMenu();
      $("#colorscreen").remove();
     $("body").append('<div id="colorscreen" class="animated"></div>');
     $("#colorscreen").addClass("fadeInUpBig");
      $('.fadeInUpBig').css('background-color', 'rgba(13,135,22,0.3)');