function checkValidation()
    {
        var strFirstName        =   document.getElementById('txt_first_name').value;
        var strLastName         =   document.getElementById('txt_last_name').value;
        var strSpeciality       =   document.getElementById('slt_speciality_menu').value;
        var intPhone            =   document.getElementById('txt_phone').value;
        var strEmail            =   document.getElementById('txt_email').value;
        var strCode             =   document.getElementById('txt_code').value;
        var strErrorMsg         =   "";
        var blnValidate         =   true;
        
        if(strFirstName == '' || strFirstName == null)
        {
            strErrorMsg += "Please enter value for First Name.\n";
            blnValidate = false;
        }
        if(strLastName == '' || strLastName == null)
        {
            strErrorMsg += "Please enter value for Last Name.\n";
            blnValidate = false;
        }
        if(strSpeciality == 0)
        {
            strErrorMsg += "Please select a Speciality.\n";
            blnValidate = false;
        }
        if(intPhone == '' || intPhone == null)
        {
            strErrorMsg += "Please enter value for Phone.\n";
            blnValidate = false;
        }
        if(strEmail == '' || strEmail == null)
        {
            strErrorMsg += "Please enter value for Email Address.\n";
            blnValidate = false;
        }
        else
        {
           var strReg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
           if(strReg.test(strEmail) == false)
           {
                strErrorMsg += "Please enter a Valid Value for Email Address.\n";
                blnValidate = false;
           }
        }

        if(strCode == '' || strCode == null)
        {
            strErrorMsg += "Please enter Verification Code.\n";
            blnValidate = false;
        }

        if(blnValidate != true)
        {
            alert(strErrorMsg);
            return false;
        }
        else
        {
            document.form_req.action='../request_demo_action.php';
            document.form_req.submit();
        }
    }