function detect()
{
	var isValid = 0;
	if (document.getElementById)
	  isValid = 1; 
	
	if (isValid == 1)
	{
		var uaString = navigator.userAgent;
		uaString = uaString.toLowerCase();
		if ((uaString.indexOf('mozilla') >= 0 && 
			((uaString.indexOf('msie') >= 0) ||	
			(uaString.indexOf('firefox') >= 0) ||	
			(uaString.indexOf('opera') >= 0) ||
			(uaString.indexOf('gecko') >= 0))
		) || (uaString.indexOf('opera') >= 0))
			return true;
		else
			return false;
	}
	else
		return false;
}