function checkPhone(phone)
{
   if (phone.length == 0)
        return false; 
   var stripped = phone.replace(/[\+\(\)\.\-\ ]/g, '');    
   if (stripped.length == 0)
        return false;
  
   if (isNaN(stripped)) {
        return false;
   } else if (!(stripped.length > 6)) {
        return false;
   }
    return true;
}

function insertAfter( referenceNode, newNode )
{
    referenceNode.parentNode.insertBefore( newNode, referenceNode.nextSibling );
}
function validateForm()
{            
    var phone  = document.forms.contact_form.phone;
    var email  = document.forms.contact_form.email;
    var name   = document.forms.contact_form.name;
    
    var valid  = true;
    var error = "";
    
    var validRegExp = /^[^@ ]+@[^@ ]+.[a-z]{2,}$/i;
    if (email.value.search(validRegExp) == -1)
    {
        document.getElementById('error1').style.display = 'block';
        valid = false
    }
    else
    {
        document.getElementById('error1').style.display = 'none';
    }
    
    if (checkPhone(phone.value) == false)
    {
        document.getElementById('error2').style.display = 'block';
        valid = false;
    }
    else
        document.getElementById('error2').style.display = 'none';
        
    if (name.value.length == 0)
    {
        document.getElementById('error3').style.display = 'block';
        valid = false;
    }
    else
    {
        document.getElementById('error3').style.display = 'none';
    }
    
    return valid;
}