Here I create a Captcha Code with JavaScript.
Step 1:
In the (.aspx) page we write the following Code:
<%@ Page Language="C#"
AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
<script language="javascript">
var a
= 49, b = 65;
var c
= 100;
var d
= 70;
function
show() {
if
(a == 57) {
a = 49;
}
var
main = document.getElementById('txt1');
var
a1 = String.fromCharCode(a);
var
b1 = String.fromCharCode(b);
var
c1 = String.fromCharCode(c);
var
d1 = String.fromCharCode(d);
main.value = a1 + b1 + c1 + d1;
a = a + 1;
b = b + 1;
c = c + 1;
d = d + 1;
}
</script>
<style type="text/css">
#form1
{
height: 95px;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<input type="text" id="txt1" runat="server"
style="border-style: none; border-color: inherit; border-width: medium; background-color:black; color:red; font-family: 'Curlz MT'; font-size: x-large; font-weight: bold; font-variant: normal; letter-spacing: 10pt; width: 120px; background-image: url('glitter_background_b4.gif');"
value="5AbD" />
<input type="button" onclick="show()" value="Change"
/>
</div>
<asp:TextBox ID="txtverification" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Verification"
onclick="Button1_Click" />
<asp:Label ID="lblmsg" runat="server" Font-Bold="True" ForeColor="Red"></asp:Label>
</form>
</body>
</html>
Step 2:
In the (.cs) page I write the following code for verification:
protected void
Button1_Click(object sender, EventArgs e)
{
if
(txtverification.Text == txt1.Value)
{
lblmsg.Text = "Successful";
}
else
{
lblmsg.Text = "Failure";
}
}