function ValidateInput()
    {
        if(document.getElementById('title').selectedIndex == 0)
        { 
            alert('Please specify your title.');
            return false;
        }
        
        if(document.getElementById('fullName').value == "")
        {
            alert('Please enter your full name.');
            return false;
        }
        
        if(document.getElementById('email').value == "")
        {
            alert('Please enter your email address.');
            return false;
        }
        else
        {
            if(!isValidEmail(document.getElementById('email').value))
            {
                alert('Please enter a valid email address.');
                return false;
            }
        }        
        
        if(document.getElementById('city').value == "")
        {
            alert('Please specify your city.');
            return false;
        }
        
        if(document.getElementById('country').selectedIndex == 0)
        {
            alert('Please specify your country.');
            return false;
        }
        
        if(document.getElementById('topic').selectedIndex == 0)
        {
            alert('Please specify your topic.');
            return false;
        }
        
        if(document.getElementById('feedback').value == "")
        {
            alert('Please enter your feedback.');
            return false;
        }
    }    

function isValidEmail (email)
{
 return (/^([a-z0-9_\-]+\.)*[a-z0-9_\-]+@([a-z0-9][a-z0-9\-]*[a-z0-9]\.)+[a-z]{2,4}$/i).test(email);
}