function openForm() {
    document.getElementById('contactform').style.display = 'block';
}

function checkFields(form) {
    
    var fields = ['form_initials', 'form_lastname', 'form_question', 'form_email'];
    var error  = [];
    
    for (var i in fields) {
        if (!form.elements[fields[i]].value) {
	        form.elements[fields[i]].className = 'error';
	        error.push(fields[i]); 
        } else {
            form.elements[fields[i]].className = '';
        }
    }
    
    if (error.length) {
        return false;
    } else {
	    changeAction(form);
	    return true;
	}
}

function changeAction(form) {
    form.action = '/residential_contact.php';
}