function view_navigator(no) {
        if (no==2) {return navigator.userAgent;}
		var Sys = {};
        var ua = navigator.userAgent.toLowerCase();
        var s; var crtn;
        (s = ua.match(/rv:([\d.]+)\) like gecko/)) ? Sys.ie = s[1] :
        (s = ua.match(/msie ([\d.]+)/)) ? Sys.ie = s[1] :
        (s = ua.match(/firefox\/([\d.]+)/)) ? Sys.firefox = s[1] :
        (s = ua.match(/chrome\/([\d.]+)/)) ? Sys.chrome = s[1] :
        (s = ua.match(/opera.([\d.]+)/)) ? Sys.opera = s[1] :
        (s = ua.match(/version\/([\d.]+).*safari/)) ? Sys.safari = s[1] : 0;
        (s = ua.match(/edge.([\d.]+)/)) ? Sys.edge = s[1] : 0;
        
        if (Sys.ie) {crtn = (no) ? 'IE' : 'IE: ' + Sys.ie;}
        if (Sys.firefox) {crtn = (no) ? 'Firefox' : 'Firefox: ' + Sys.firefox;}
        if (Sys.chrome) {crtn = (no) ? 'Chrome' : 'Chrome: ' + Sys.chrome;}
        if (Sys.opera) {crtn = (no) ? 'Opera' : 'Opera: ' + Sys.opera;}
        if (Sys.safari) {crtn = (no) ? 'Safari' : 'Safari: ' + Sys.safari;}
        if (Sys.edge) {crtn = (no) ? 'Edge' : 'Edge: ' + Sys.edge;}
		if (!crtn) {crtn = 'unknown';}
		return crtn
    }