How to draw captcha in HTML page through javascript

 
    <script type="text/javascript">
   //Created captcha  
    function DrawCaptcha()
    {
        var x = Math.ceil(Math.random() * 10)+ '';
        var y = Math.ceil(Math.random() * 10)+ '';       
        var z = Math.ceil(Math.random() * 10)+ '';  
        
        var code = x + ' ' + y + ' ' + ' ' + z ;
        document.getElementById("tCaptcha").value = code
    }

    // generated security 
    function ValidCaptcha(){
        var string1 = removeSpaces(document.getElementById('tCaptcha').value);
        var string2 = removeSpaces(document.getElementById('tInput').value);
        if (string1 == string2) return true;        
        return false;
        
    }

 function showRecaptcha(element) 
    {      
        Recaptcha.create(
            "http://www.google.com/recaptcha/api/js/recaptcha_ajax.js", 
            element, 
            {
                    lang: "<%=LanguageCode %>",
                    theme: "red"
                    //callback: Recaptcha.focus_response_field
            });
    }