//usage
//-----
//within the body, before the <Form>, add <script type="text/javascript" src="http://www.nn.net/security/security.js"> </script>
//in the <Form> tag add onSubmit="return checkCode(this.inp_sCode.value, this.inp_hCode.value);"

//within the form, add the following lines:
//<input type="hidden" name="inp_iCode" value="YES">
//<script language="JavaScript">getImage()</script>



function encryptIt(to_enc)
{
	var xor_key="5";
	var the_res="";//the result will be here
	for(i=0;i<to_enc.length;++i)
	{
		the_res+=String.fromCharCode(xor_key^to_enc.charCodeAt(i));
	}
	return the_res;
}

function decryptIt(to_dec)
{
	var xor_key="5";
	var the_res="";//the result will be here
	for(i=0;i<to_dec.length;i++)
	{
		the_res+=String.fromCharCode(xor_key^to_dec.charCodeAt(i));
	}
	return the_res;
}

function getImage(form)
{
	images = new Array(30);
	values = new Array(30);

	images[0]  = "secureimage1";
	values[0]  = "AE5HB";
	images[1]  = "secureimage2";
	values[1]  = "BDE5H";
	images[2]  = "secureimage3";
	values[2]  = "BAF58";
	images[3]  = "secureimage4";
	values[3]  = "BH28G";
	images[4]  = "secureimage5";
	values[4]  = "HA35B";
	images[5]  = "secureimage6";
	values[5]  = "D5ABF";
	images[6]  = "secureimage7";
	values[6]  = "BDF3E";
	images[7]  = "secureimage8";
	values[7]  = "H2AE8";
	images[8]  = "secureimage9";
	values[8]  = "B28FD";
	images[9]  = "secureimage10";
	values[9]  = "2AD5B";
	images[10] = "secureimage11";
	values[10] = "28BHD";
	images[11] = "secureimage12";
	values[11] = "D8D5E";
	images[12] = "secureimage13";
	values[12] = "DF8BA";
	images[13] = "secureimage14";
	values[13] = "F38BH";
	images[14] = "secureimage15";
	values[14] = "H2B52";
	images[15] = "secureimage16";
	values[15] = "A8DEF";
	images[16] = "secureimage17";
	values[16] = "3BBH3";
	images[17] = "secureimage18";
	values[17] = "H5AEB";
	images[18] = "secureimage19";
	values[18] = "H583D";
	images[19] = "secureimage20";
	values[19] = "BE5A3";
	images[20] = "secureimage21";
	values[20] = "5BFEH";
	images[21] = "secureimage22";
	values[21] = "2B2BD";
	images[22] = "secureimage23";
	values[22] = "EB25D";
	images[23] = "secureimage24";
	values[23] = "D8HBF";
	images[24] = "secureimage25";
	values[24] = "5B5DH";
	images[25] = "secureimage26";
	values[25] = "A2H38";
	images[26] = "secureimage27";
	values[26] = "BF358";
	images[27] = "secureimage28";
	values[27] = "8B53H";
	images[28] = "secureimage29";
	values[28] = "BH8F5";
	images[29] = "secureimage30";
	values[29] = "ADB88";

	index = Math.floor(Math.random()*images.length);
	document.writeln('<div align="center">');
	document.writeln('<input type="hidden" name="inp_hCode" value="'+encryptIt(values[index])+'">');
	document.writeln('<input type="hidden" name="inp_cCode" value="'+values[index]+'">');
	document.writeln('<IMG SRC="http://www.nn.net/security/images/'+images[index]+'.gif" border="0" width="100" height="50" hspace="10" vspace="10" alt=""><br>')
	document.writeln('Enter the Code Above <input type="text" name="inp_sCode" value="" size="7" maxlength="5">');
	document.writeln('</div>');
}

function checkCode(uInput, sCode)
{
	if (uInput.toUpperCase()!=decryptIt(sCode))
  {
    alert('Please Enter The Security Code Exactly As It Appears'); 
		return false;
	}
	return true;
}