its urgent please check this once

Question

hii i hav a problem with thsi code
check it once
if (!this.IsPostBack)

// Create a random code and store it in the Session object.

this.Session["CaptchaImageText"] = GenerateRandomCode();

else

{

// On a postback, check the user input.

if (this.CodeNumberTextBox.Text ==

this.Session["CaptchaImageText"].ToString())

{

// Display an informational message.

this.MessageLabel.CssClass = "info";

this.MessageLabel.Text = "Correct!";

}

else

{

//Display an error message.

this.MessageLabel.CssClass = "error";

this.MessageLabel.Text = "ERROR: Incorrect, try again.";

// Clear the input and create a new random code.

this.CodeNumberTextBox.Text = "";

this.Session["CaptchaImageText"] = GenerateRandomCode();

}

}

}
the second else is directly executing without anywrong entry of text
so please tell how to correct thsi code