Simple JavaScript Captcha Code

mahakgupta

5.00/5 (5 votes)

Jun 24, 2010

CPOL

25008

Simple JavaScript Captcha Code

Steps:-> 1. In the .aspx page.I write the javascript 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 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>
&nbsp;&nbsp;&nbsp;&nbsp;
    <asp:Button ID="Button1" runat="server" Text="Verification"
        onclick="Button1_Click" />
    &nbsp;&nbsp;&nbsp;&nbsp;
    <asp:Label ID="lblmsg" runat="server" Font-Bold="True" ForeColor="Red"></asp:Label>
    </form>
</body>
</html>

2. In the .cs page:->

protected void Button1_Click(object sender, EventArgs e)
   {
       if (txtverification.Text == txt1.Value)
       {
           lblmsg.Text = "Successfull";
       }
       else
       {
           lblmsg.Text = "Failure";
       }
   }