Generate 16-bit string (No Duplicates)

Using System;

Namespace Getsysid
{
<summary>
Summary description of the SYSID.
</summary>
public class Getsysid
{
Public Getsysid ()
{
//
TODO: Add constructor logic here
//
}
public string Sysid ()
{
String Sysid,lc,lc1,ss;

String year,day,hour,minute,sec,msec;
Year = System.DateTime.Now.Year.ToString ();
Day = System.DateTime.Now.DayOfYear.ToString ();
hour = System.DateTime.Now.Hour.ToString ();
minute = DateTime.Now.Minute.ToString ();
SEC = DateTime.Now.Second.ToString ();
msec = DateTime.Now.Millisecond.ToString ();

if (year). Length = = 4)
{
Year = year. Substring (2,2);
}

LC1 = "";
LC1 = LC1 + changstr (true,year, "0", 2);
LC1 = LC1 + changstr (true,day, "0", 3);
LC1 = LC1 + changstr (true,hour, "0", 2);
LC1 = LC1 + changstr (true,sec, "0", 2);

Long T;
t = Convert.toint64 (LC1);

LC1 = "";
LC1 = Inttohex (t,8);

SS = Changstr (True,sec, "0", 2);
t = Convert.toint64 (ss);
LC1 = LC1 + Inttohex (t,2);
LC1 = LC1 + Inttohex (Convert.toint64 (msec), 3);

64 in-system
SS = System.Guid.NewGuid (). ToString ();
LC = ss. Substring (0,8);
LC = CHECKID (LC);

LC1 = LC1 + changstr (TRUE,LC, "0", 8);
SS = "";

SS = LC1. Substring (1,8);
Sysid = HexTo36 (ss,6);
Ss= LC1. Substring (8,13);
Sysid = Sysid + HexTo36 (ss,10);

return sysid;
}

Convert to hexadecimal data
private string Inttohex (long Num,int len)
{
String Lchexstr,strhex;
Lchexstr = "0123456789ABCDEF";
int lmod,len1;
Lmod = 0;
Strhex = "";

while (num > 0)
{
Lmod = (int) (num% 16);
num = NUM/16;
Strhex = Lchexstr.substring (lmod, 1) + Strhex;
}

Len1 = Strhex.length;
if (Len1 < len)
Strhex = Changstr (True,strhex, "0", Len);
return strhex;
}

Change the string to a specified length
private string Changstr (bool bisf,string strhex,string substr,int @len)
{
int len1;
Len1 = Len-strhex.length;
for (int i = 0; i < len1; i++)
{
if (BISF = = True)
Strhex = SubStr + Strhex;
Else
Strhex = Strhex + subStr;
}
return strhex;
}

Check string
private string Checkid (String str)
{
String outstr;
Char charstr;
int Len;
outstr = "";

str = str. ToUpper ();
Len = str. Length;

for (int i =0; i < Len; i++)
{
Charstr = Str[i];
if ((((int) charstr >=) && ((int) charstr <= 59) | | (((int) charstr >=) && ((int) charstr <= 70))
{
outstr = outstr + charstr;
}
Else
outstr = outstr + inttohex ((int) charstr,0);
}
if (Outstr.length > 8)
outstr = outstr.substring (0,8);
return outstr;
}

Convert to 36 binary
private string HexTo36 (string Strhex,int len)
{
String Str62,lc62str;
Lc62str = "0123456789" + "abcdefghijklmnopqrstuvwxyz";
Str62 = "";
int lmod = 0;
Long num1 = 0;

Convert to Decimal
Long Lnshex = 1;
Strhex = Strhex.toupper ();
int len1;
Len1 = Strhex.length;
while (Len1 > 0)
{
Char SS;
SS = strhex[(len1-1)];
NUM1 = Num1 + (Lc62str.indexof (ss)) * LNSHEX;
if (len1 = 1)
Lnshex = 16;
Else
Lnshex = Lnshex * 16;
Len1--;
LISTBOX1.ITEMS.ADD (NUM1. ToString ());
}

MessageBox.Show (NUM1. ToString ());
Convert to 36 binary
Str62 = "";
while (Num1 > 0)
{
Lmod = (int) (num1% 36);
NUM1 = NUM1/36;
Str62 = Lc62str.substring (lmod, 1) + str62;
}
Len1 = str62. Length;

if (Len1 < len)
{
Str62 = Changstr (true,str62, "0", Len);
}
return str62;
}
}
}