How to Create CAPTCHA Protection using PHP

there are following stpes
1. html code
<img src="/captcha.php/?rand=0.608989860869691" id="captcha_image"/>
<a href="javascript:void(0);" onClick="refreshcaptcha();" >Refresh</a>
<input type="text" name="norobot" id="norobot" value="Enter Image Code" />

2. js
function refreshcaptcha(){
    var capimage = document.getElementById('captcha_image').src;  
    var full_img=capimage.split('rand=');  
    document.getElementById('captcha_image').setAttribute('src', full_img[0]+'rand='+Math.random());
}

3.captcha.php
$randomnr = rand(1000, 9999);
$session["randomnr"] = md5($randomnr));
   
   
    $im = imagecreatetruecolor(100, 38);

    $white = imagecolorallocate($im, 255, 255, 255);
    $grey = imagecolorallocate($im, 150, 150, 150);
    $black = imagecolorallocate($im, 0, 0, 0);

    imagefilledrectangle($im, 0, 0, 200, 35, $black);

    //path to font - this is just an example you can use any font you like:
   
    $font =  '/font/karate/Karate.ttf';

    imagettftext($im, 20, 4, 22, 30, $grey, $font, $randomnr);

    imagettftext($im, 20, 4, 15, 32, $white, $font, $randomnr);
    
    //die(111);
    //prevent caching on client side:
    header("Expires: Wed, 1 Jan 1997 00:00:00 GMT");
    header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
    header("Cache-Control: no-store, no-cache, must-revalidate");
    header("Cache-Control: post-check=0, pre-check=0", false);
    header("Pragma: no-cache");

    header ("Content-type: image/gif");
    imagegif($im);
    imagedestroy($im);
    exit;

4. On post action file
if (md5($data['norobot']) == $session["randomnr"])    {
                // here you  place code to be executed if the captcha test passes
 }    else { 
                // here you  place code to be executed if the captcha test fails
                    echo "Please enter correct code.";
                    return;
}

Magento : Create an attribute for customer mobile number

Consider package : Bd_Customermobile

1. Bd_Customermobile.xml

<?xml version="1.0"?>
<config>
  <modules>
    <Bd_Customermobile>
      <active>true</active>
      <codePool>local</codePool>
      <version>0.1.0</version>
    </Bd_Customermobile>
  </modules>
</config>

2. config.xml
<?xml version="1.0"?>
<config>
  <modules>
    <Bd_Customermobile>
      <version>0.1.0</version>
    </Bd_Customermobile>
  </modules>
  <global>
    <helpers>
      <customermobile>
        <class>Bd_Customermobile_Helper</class>
      </customermobile>
    </helpers>
    <models>
      <customermobile>
        <class>Bd_Customermobile_Model</class>
        <resourceModel>customermobile_mysql4</resourceModel>
      </customermobile>
    </models>
    <resources>
      <customerattribute_setup>
        <setup>
          <module>Bd_Customermobile</module>
          <class>Mage_Customer_Model_Entity_Setup</class>
        </setup>
        <connection>
          <use>core_setup</use>
        </connection>
      </customerattribute_setup>
      <customerattribute_write>
        <connection>
          <use>core_write</use>
        </connection>
      </customerattribute_write>
      <customerattribute_read>
        <connection>
          <use>core_read</use>
        </connection>
      </customerattribute_read>
    </resources>
  </global>
</config>

3. mysql4-install-0.1.0.php
<?php
$installer = $this;
$installer->startSetup();


$installer->addAttribute("customer", "bd_customer_mobile",  array(
    "type"     => "varchar",
    "backend"  => "",
    "label"    => "Customer Mobile",
    "input"    => "text",
    "source"   => "",
    "visible"  => true,
    "required" => false,
    "default" => "",
    "frontend" => "",
    "unique"     => false,
    "note"       => "Additional attribute for mobile number"

    ));

        $attribute   = Mage::getSingleton("eav/config")->getAttribute("customer", "bd_customer_mobile");

       
$used_in_forms=array();

$used_in_forms[]="adminhtml_customer";
        $attribute->setData("used_in_forms", $used_in_forms)
        ->setData("is_used_for_customer_segment", true)
        ->setData("is_system", 0)
        ->setData("is_user_defined", 1)
        ->setData("is_visible", 1)
        ->setData("sort_order", 100)
        ;
        $attribute->save();
   
   
   
$installer->endSetup();
    

Magento: Mobile number validation using custom class

HTML code

<input type="text" name="telephone" id="telephone" value="<?php echo $this->htmlEscape($this->getFormData()->getTelephone()) ?>" title="<?php echo $this->__('Telephone') ?>" class="input-text validate-custommobile" />



Js code

<script type="text/javascript">
    //<![CDATA[

if(Validation) {
        Validation.addAllThese([
        ['validate-custommobile','Enter correct mobile number',
        function(v){
        var timePat ="^((\+){0,1}91(\s){0,1}(\-){0,1}(\s){0,1}){0,1}9[0-9](\s){0,1}(\-){0,1}(\s){0,1}[1-9]{1}[0-9]{7}$";
        // var matchArray = v.match(timePat);
        if(v.length > 0){
        if(v.length !=10){
            return false;
           }else if(v[0] != 9 || v[1] != 1 ){

            //return false;
           }else if(v[2]!=9 && v[2]!=8 && v[2]!=7){

            return false;
           }


        return true;

        }else {
        return false;
        }

        }
        ]])};
        var dataForm = new VarienForm('form-id', true);

//]]>

</script>