function getOS()
{
var OS = navigator.userAgent;
var OS_in_orde = true
if ((OS.indexOf("Windows NT 7.0")!=-1) || (OS.indexOf("Windows NT 6.1")!=-1))
OS="Windows 7";
else if ((OS.indexOf("Windows NT 6.0")!=-1))
OS="Windows Vista";
else if ((OS.indexOf("Windows NT 5.2")!=-1))
OS="Windows Server 2003 / Windows XP";
else if ((OS.indexOf("Windows NT 5.1")!=-1) || (OS.indexOf("Windows XP")!=-1) || (OS.indexOf("Windows NT 5,1")!=-1))
OS="Windows XP";
else if ((OS.indexOf("Windows ME")!=-1) || (OS.indexOf("Win 9x 4.90")!=-1))
OS="Windows ME";
else if ((OS.indexOf("Windows NT 5.0")!=-1) || (OS.indexOf("Windows 2000")!=-1) || (OS.indexOf("Windows NT5.0")!=-1) || (OS.indexOf("Windows NT5")!=-1))
OS="Windows 2000";
else if ((OS.indexOf("Windows 98")!=-1) || (OS.indexOf("Win98")!=-1))
OS="Windows 98";
else
OS="Windows";
return OS;
}