Define Globally Class

public class clsGENERAL

{

    string str = ConfigurationManager.ConnectionStrings["d"].ConnectionString;

    SqlConnection con;

    SqlCommand cmd;

    SqlDataAdapter da;

    DataSet ds = new DataSet();

    public clsGENERAL()

    {

       

    }

    public int FireQuery(string qry)

    {

        con = new SqlConnection(str);

        con.Open();

        cmd = new SqlCommand(qry, con);

        int i = cmd.ExecuteNonQuery();

        con.Close();

        return i;

    }

    public DataSet SelectQuery(string qry)

    {

        con = new SqlConnection(str);

        con.Open();

        ds.Reset();

        da = new SqlDataAdapter(qry, con);

        da.Fill(ds);

        return ds;

    }

}

Encrypt/Decrypt Querystring

 First Create Class as Encrypt.cs



using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Security.Cryptography;

using System.IO;

using System.Text;



/// <summary>

/// Summary description for Encrypt

/// </summary>

public class EncryptDecryptQueryString

{

    private byte[] key = { };

    private byte[] IV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xab, 0xcd, 0xef };

    public string Decrypt(string stringToDecrypt, string sEncryptionKey)

    {

        byte[] inputByteArray = new byte[stringToDecrypt.Length + 1];

        try

        {

            key = System.Text.Encoding.UTF8.GetBytes(sEncryptionKey);

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            inputByteArray = Convert.FromBase64String(stringToDecrypt);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms,

              des.CreateDecryptor(key, IV), CryptoStreamMode.Write);

            cs.Write(inputByteArray, 0, inputByteArray.Length);

            cs.FlushFinalBlock();

            System.Text.Encoding encoding = System.Text.Encoding.UTF8;

            return encoding.GetString(ms.ToArray());

        }

        catch (Exception e)

        {

            return e.Message;

        }

    }



    public string Encrypt(string stringToEncrypt, string SEncryptionKey)

    {

        try

        {

            key = System.Text.Encoding.UTF8.GetBytes(SEncryptionKey);

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] inputByteArray = Encoding.UTF8.GetBytes(stringToEncrypt);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms,

              des.CreateEncryptor(key, IV), CryptoStreamMode.Write);

            cs.Write(inputByteArray, 0, inputByteArray.Length);

            cs.FlushFinalBlock();

            return Convert.ToBase64String(ms.ToArray());

        }

        catch (Exception e)

        {

            return e.Message;

        }

    }

}

---------------------

Now For Encrypt...

FirstPage.aspx

 protected void Button1_Click(object sender, EventArgs e)

    {

        string strName = "", strAge = "", strPhone = "";

        strName = "Dhruval";

        string strURL = "Executive.aspx?";

        if (HttpContext.Current != null)

        {

            string strURLWithData = strURL +

              EncryptQueryString(string.Format("Name={0}",

              strName));

            HttpContext.Current.Response.Redirect(strURLWithData);

        }

        else

        { }

    }



public string EncryptQueryString(string strQueryString)

    {

        EncryptDecryptQueryString objEDQueryString = new EncryptDecryptQueryString();

        return objEDQueryString.Encrypt(strQueryString, "r0b1nr0y");

    }



-------------------

SecondPage.aspx

 if (!IsPostBack)

        {

            string strReq = "";

            strReq = Request.RawUrl;

            strReq = strReq.Substring(strReq.IndexOf('?') + 1);



            if (!strReq.Equals(""))

            {

                strReq = DecryptQueryString(strReq);



                //Parse the value... this is done is very raw format..

                //you can add loops or so to get the values out of the query string...

                string[] arrMsgs = strReq.Split('&');

                string[] arrIndMsg;

                string strName = "", strAge = "", strPhone = "";

                arrIndMsg = arrMsgs[0].Split('='); //Get the Name

                strName = arrIndMsg[1].ToString().Trim();

                //arrIndMsg = arrMsgs[1].Split('='); //Get the Age

                //strAge = arrIndMsg[1].ToString().Trim();

                //arrIndMsg = arrMsgs[2].Split('='); //Get the Phone

                //strPhone = arrIndMsg[1].ToString().Trim();



                lblName.Text = strName;



            }

            else

            {

                Response.Redirect("Page1.aspx");

            }

        } 

MIME For Downloading Documents

Multipurpose Internet Mail Extensions (MIME) is an Internet standard that extends the format of e-mail to support:

• Text in character sets other than ASCII
• Non-text attachments
• Message bodies with multiple parts
• Header information in non-ASCII character sets

MIME's use, however, has grown beyond describing the content of e-mail to describe content type in general, including for the web (see Internet media type) and as a storage for rich content in some commercial products (e.g., IBM Lotus Domino and IBM Lotus Quickr).
Virtually all human-written Internet e-mail and a fairly large proportion of automated e-mail is transmitted via SMTP in MIME format. Internet e-mail is so closely associated with the SMTP and MIME standards that it is sometimes called SMTP/MIME e-mail.


Code For Dynamic MIME Types:
string Path = "~/images/arrow.gif";
        string FileName = "arrow";
        string Extension = ".gif";
        string type = "";
        if (Extension != null)
        {
            switch (Extension.ToLower())
            {
                case ".htm":
                case ".html":
                    type = "text/HTML";
                    break;
                case ".doc":
                case ".rtf":
                case ".docx":
                    type = "Application/msword";
                    break;
                case ".gif":
                    type = "image/gif";
                    break;
            }
            Response.AppendHeader("content-disposition",
        "attachment; filename=" + FileName);
            if (type != "")
                Response.ContentType = type;
            Response.WriteFile(Path);
            Response.End();




Some Other MIME Examples:

file type	MIME type
ai	application/postscript
aif	audio/x-aiff
aifc	audio/x-aiff
aiff	audio/x-aiff
asc	text/plain
atom	application/atom+xml
au	audio/basic
avi	video/x-msvideo
bcpio	application/x-bcpio
bin	application/octet-stream
bmp	image/bmp
cdf	application/x-netcdf
cgm	image/cgm
class	application/octet-stream
cpio	application/x-cpio
cpt	application/mac-compactpro
csh	application/x-csh
css	text/css
dcr	application/x-director
dif	video/x-dv
dir	application/x-director
djv	image/vnd.djvu
djvu	image/vnd.djvu
dll	application/octet-stream
dmg	application/octet-stream
dms	application/octet-stream
doc	application/msword
dtd	application/xml-dtd
dv	video/x-dv
dvi	application/x-dvi
dxr	application/x-director
eps	application/postscript
etx	text/x-setext
exe	application/octet-stream
ez	application/andrew-inset
gif	image/gif
gram	application/srgs
grxml	application/srgs+xml
gtar	application/x-gtar
hdf	application/x-hdf
hqx	application/mac-binhex40
htm	text/html
html	text/html
ice	x-conference/x-cooltalk
ico	image/x-icon
ics	text/calendar
ief	image/ief
ifb	text/calendar
iges	model/iges
igs	model/iges
jnlp	application/x-java-jnlp-file
jp2	image/jp2
jpe	image/jpeg
jpeg	image/jpeg
jpg	image/jpeg
js	application/x-javascript
kar	audio/midi
latex	application/x-latex
lha	application/octet-stream
lzh	application/octet-stream
m3u	audio/x-mpegurl
m4a	audio/mp4a-latm
m4b	audio/mp4a-latm
m4p	audio/mp4a-latm
m4u	video/vnd.mpegurl
m4v	video/x-m4v
mac	image/x-macpaint
man	application/x-troff-man
mathml	application/mathml+xml
me	application/x-troff-me
mesh	model/mesh
mid	audio/midi
midi	audio/midi
mif	application/vnd.mif
mov	video/quicktime
movie	video/x-sgi-movie
mp2	audio/mpeg
mp3	audio/mpeg
mp4	video/mp4
mpe	video/mpeg
mpeg	video/mpeg
mpg	video/mpeg
mpga	audio/mpeg
ms	application/x-troff-ms
msh	model/mesh
mxu	video/vnd.mpegurl
nc	application/x-netcdf
oda	application/oda
ogg	application/ogg
pbm	image/x-portable-bitmap
pct	image/pict
pdb	chemical/x-pdb
pdf	application/pdf
pgm	image/x-portable-graymap
pgn	application/x-chess-pgn
pic	image/pict
pict	image/pict
png	image/png
pnm	image/x-portable-anymap
pnt	image/x-macpaint
pntg	image/x-macpaint
ppm	image/x-portable-pixmap
ppt	application/vnd.ms-powerpoint
ps	application/postscript
qt	video/quicktime
qti	image/x-quicktime
qtif	image/x-quicktime
ra	audio/x-pn-realaudio
ram	audio/x-pn-realaudio
ras	image/x-cmu-raster
rdf	application/rdf+xml
rgb	image/x-rgb
rm	application/vnd.rn-realmedia
roff	application/x-troff
rtf	text/rtf
rtx	text/richtext
sgm	text/sgml
sgml	text/sgml
sh	application/x-sh
shar	application/x-shar
silo	model/mesh
sit	application/x-stuffit
skd	application/x-koan
skm	application/x-koan
skp	application/x-koan
skt	application/x-koan
smi	application/smil
smil	application/smil
snd	audio/basic
so	application/octet-stream
spl	application/x-futuresplash
src	application/x-wais-source
sv4cpio	application/x-sv4cpio
sv4crc	application/x-sv4crc
svg	image/svg+xml
swf	application/x-shockwave-flash
t	application/x-troff
tar	application/x-tar
tcl	application/x-tcl
tex	application/x-tex
texi	application/x-texinfo
texinfo	application/x-texinfo
tif	image/tiff
tiff	image/tiff
tr	application/x-troff
tsv	text/tab-separated-values
txt	text/plain
ustar	application/x-ustar
vcd	application/x-cdlink
vrml	model/vrml
vxml	application/voicexml+xml
wav	audio/x-wav
wbmp	image/vnd.wap.wbmp
wbmxl	application/vnd.wap.wbxml
wml	text/vnd.wap.wml
wmlc	application/vnd.wap.wmlc
wmls	text/vnd.wap.wmlscript
wmlsc	application/vnd.wap.wmlscriptc
wrl	model/vrml
xbm	image/x-xbitmap
xht	application/xhtml+xml
xhtml	application/xhtml+xml
xls	application/vnd.ms-excel
xml	application/xml
xpm	image/x-xpixmap
xsl	application/xml
xslt	application/xslt+xml
xul	application/vnd.mozilla.xul+xml
xwd	image/x-xwindowdump
xyz	chemical/x-xyz
zip	application/zip