<table>
<tr>
<td>Uploaded Image
</td>
<td>

<asp:FileUpload ID="fil1" runat="server"/>

</td>
</tr>
<tr>
<td colspan="2" align="center">

<asp:Button ID="btnsubmit" runat="server" Text="Submit" CssClass="btn" 
OnClientClick="StartProgressBar()" OnClick="btnsubmit_Click"/>

</td>
</tr>
<tr>
<td colspan="2" align="center">

<asp:Label ID="lblmessage" CssClass="lbl" runat="server"></asp:Label>

</td>
</tr>
</tr>
</table>

protected void btnsubmit_Click(object sender, EventArgs e)

{

try

{

HttpPostedFile Myimage;

Myimage = fil1.PostedFile;

if (Myimage.ContentLength == 0)

{

lblmessage.Text = "Please Upload Image.";

}

else

{

if (Path.GetExtension(Myimage.FileName).ToLower() == ".jpg" || Path.GetExtension(Myimage.FileName).ToLower() == ".png" || Path.GetExtension(Myimage.FileName).ToLower() == ".gif" )

{

int bytesval = fil1.PostedFile.ContentLength;

int kilobytesval = bytesval / 1024;

System.Threading.Thread.Sleep(2000);

fil1.PostedFile.SaveAs(@"E:\ images\" + GenerateString() + "" + Path.GetExtension(Myimage.FileName));

lblmessage.Text = "Image saved successfully" + kilobytesval + " KB <br>";

}

else

{

lblmessage.Text="Invalid Image Format. The Image Extension Must Be .jpg.";

}

}

}

catch (Exception ex)

{

lblmessage.Text = ex.ToString();

}

}

public string GenerateString()

{

string allowedChars = "a,b,c,d,e,f,g,h,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,";

allowedChars += "A,B,C,D,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z,";

allowedChars += "2,3,4,5,6,7,8,9";

char[] sep = { ',' };

string[] arr = allowedChars.Split(sep);

string passwordString = "";

string temp;

Random rand = new Random();

for (int i = 0; i < 6; i++)

{

temp = arr[rand.Next(0, arr.Length)];

passwordString += temp;

}

return passwordString;

}