Edit in JSFiddle

$(document).on('pageinit', '#index', function(){ 
    $(document).on('click', '#panel-example', function(){ 
        $( "#mypanel" ).panel().panel( "open" );
    });  
});
<!DOCTYPE html>
<html>
    <head>
        <title>jQM Complex Demo</title>
        <meta http-equiv='Content-Type' content='text/html; charset=utf-8'/>
        <meta name="viewport" content="width=device-width; initial-scale=1.0; maximum-scale=1.0; minimum-scale=1.0; user-scalable=no; target-densityDpi=device-dpi"/>
        <link rel="stylesheet" href="http://code.jquery.com/mobile/1.4.0-alpha.1/jquery.mobile-1.4.0-alpha.1.min.css" />
        <!--<script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>-->
        <script src="http://code.jquery.com/mobile/1.4.0-alpha.1/jquery.mobile-1.4.0-alpha.1.min.js"></script>
    </head>
    <body>          
        <div data-role="page" id="index" data-theme="a" >
            <div data-role="header">
                <h3>
                    First Page
                </h3>
                <a href="#second" class="ui-btn-right">Next</a>
            </div>
            
            <div data-role="content">
                <form>
                    <a data-role="button" id="panel-example">Open Outside Panel</a>
                    <label for="flip-checkbox">New Flipswitch</label>
                    <input data-role="flipswitch" name="flip-checkbox" id="flip-checkbox" type="checkbox"/>            
                    <input data-type="search" id="searchForSelect"/>
                    <select id="anotherSelect" data-filter="true" data-input="#searchForSelect">
                        <option value="A">Option A</option>
                        <option value="B">Option B</option>
                        <option value="C">Option C</option>
                        <option value="D">Option D</option>
                        <option value="E">Option E</option>
                        <option value="F">Option F</option>
                        <option value="G">Option G</option>
                        <option value="H">Option H</option>
                        <option value="I">Option I</option>
                        <option value="J">Option J</option>
                    </select>                    
                </form>               
            </div>
            
            <div data-role="footer" data-position="fixed">
                
            </div>
        </div> 
        <div data-role="panel" id="mypanel">
            This is outside panel, it can be reused among pages
        </div><!-- /panel -->             
        <div data-role="page" id="second" data-theme="a" >
            <div data-role="header">
                <h3>
                    Second Page
                </h3>
                <a href="#index" class="ui-btn-left">Back</a>
            </div>
            
            <div data-role="content">
                
            </div>
            
            <div data-role="footer" data-position="fixed">
                
            </div>
        </div>  
    </body>
</html>