function validate_form()
{
	var return_val = true;
	
	required_field = document.getElementById('required_field_name');
	if(document.interestForm.first_name.value=='' || document.interestForm.last_name.value=='') 
	{
		required_field.innerHTML = 'Please enter your first and last name.';
		required_field.style.visibility = 'visible';
		required_field.style.color = 'red';
		return_val = false;
	}
	else
	{
		required_field.style.visibility = 'hidden';
	}

	required_field = document.getElementById('required_field_address');
	if(document.interestForm.street.value=='') 
	{
		required_field.innerHTML = 'Please enter your address.';
		required_field.style.visibility = 'visible';
		required_field.style.color = 'red';
		return_val = false;
	}
	else
	{
		required_field.style.visibility = 'hidden';
	}

	required_field = document.getElementById('required_field_city_zip');
	if(document.interestForm.city.value=='' || document.interestForm.zip.value=='') 
	{
		required_field.innerHTML = 'Please enter your address, city and zip code.';
		required_field.style.visibility = 'visible';
		required_field.style.color = 'red';
		return_val = false;
	}
	else if (!validate_zip(document.interestForm.zip.value))
	{
		required_field.innerHTML = 'Please enter a valid zip code.';
		required_field.style.visibility = 'visible';
		required_field.style.color = 'red';
		return_val = false;
	}
	else
	{
		required_field.style.visibility = 'hidden';
	}
	
	required_field = document.getElementById('required_field_email');
	if(document.interestForm.email.value=='') 
	{
		required_field.innerHTML = 'Please enter your email address.';
		required_field.style.visibility = 'visible';
		required_field.style.color = 'red';
		return_val = false;
	}
	else if (!validate_email(document.interestForm.email.value))
	{
		required_field.innerHTML = 'Please enter a valid email address.';
		required_field.style.visibility = 'visible';
		required_field.style.color = 'red';
		return_val = false;
	}
	else
	{
		required_field.style.visibility = 'hidden';
	}
	
	return return_val;

	
}

function validate_email(email) 
{
	var reg = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	return reg.test(email);
}

function validate_zip(zip) 
{
	var reg = /(^\d{5}$)|(^\d{9}$)|(^\d{5}-\d{4}$)/;
	return reg.test(zip);
}