I am new to WRT development. I have to add music player of the phone in the WRT widget

i try stream remote mp3 file but i can't use window.widget.openApplication(0x102072c3,params);
And this is my code (test....)
Code:
<input type="button" value="test1" onclick="ham1()" /><br><br><br>
        <input type="button" value="test2" onclick="ham2()" /><br><br><br>
        <input type="button" value="test3" onclick="ham3()" /><br><br><br>
        <input type="button" value="test4" onclick="ham4()" /><br><br><br>
        <input type="button" value="test5" onclick="ham5()" /><br><br><br>
        
        <script>
            var a =document.getElementById("test");

          var url_mp3 ="http://www.myserver.com/media/song1.mp3"; 
            
            var open = function(params)
            {
                
                window.widget.openApplication(0x102072c3,params);
            };
            function ham1()    {
                
                var param = "4"+"<Space>"+url_mp3;
                open(param);
            }
            function ham2()    {
               
                var param = "4"+" "+url_mp3;
                open(param);
            }
            function ham3()    {
               
                var param = "4 "+url_mp3;
                open(param);
            }
            function ham4()    {
               
                var param = "4"+url_mp3;
                open(param);
            }
            function ham5()    {
                
                var param = url_mp3;
                open(param);
            }
            
            
            
            
            
        </script>

please help me.