// Determine browser and version.
	
	function Browser() {
	
	  var ua, s, i;
	
	  this.isIE    = false;  // Internet Explorer
	  this.isNS    = false;  // Netscape
	  this.version = null;
	
	  ua = navigator.userAgent;
	
	  s = "MSIE";
	  if ((i = ua.indexOf(s)) >= 0) {
	    this.isIE = true;
	    this.version = parseFloat(ua.substr(i + s.length));
	    return;
	  }
	
	  s = "Netscape6/";
	  if ((i = ua.indexOf(s)) >= 0) {
	    this.isNS = true;
	    this.version = parseFloat(ua.substr(i + s.length));
	    return;
	  }
	
	  // Treat any other "Gecko" browser as NS 6.1.
	
	  s = "Gecko";
	  if ((i = ua.indexOf(s)) >= 0) {
	    this.isNS = true;
	    this.version = 6.1;
	    return;
	  }
	}
	
var browser = new Browser();
var isGood = false;
if(( browser.isNS && browser.version >=3 ) || ( browser.isIE && browser.version >=4 )) isGood = true;