function registerValidation(f1)
{
	if (trim(f1.name.value)=='')
	{
		alert('Name field cannot be empty');
		f1.name.value = '';
		f1.name.focus();
		return false;
	}
	
	if (trim(f1.lastname.value)=='')
	{
		alert('Last name field cannot be empty');
		f1.lastname.value = '';
		f1.lastname.focus();
		return false;
	}
	
	if (trim(f1.zipcode.value)=='')
	{
		alert('Zipcode field cannot be empty');
		f1.zipcode.value = '';
		f1.zipcode.focus();
		return false;
	}
	
	if (trim(f1.address.value)=='')
	{
		alert('Address field cannot be empty');
		f1.address.value = '';
		f1.address.focus();
		return false;
	}
	
	if (trim(f1.city.value)=='')
	{
		alert('City field cannot be empty');
		f1.city.value = '';
		f1.city.focus();
		return false;
	}
	
	/**
	 * State validation
	 */
	var index = f1.state.options.selectedIndex;
	var state = f1.state.options[index].value;
	
	if (f1.state.value=='0')
	{
		alert('Please, select a state');
		f1.state.focus();
		return false;
	}
	
	if (trim(f1.email.value)=='')
	{
		alert('E-mail field cannot be empty');
		f1.email.focus();
		return false;
	}
	
	if (trim(f1.password.value)=='')
	{
		alert('Password field cannot be empty');
		f1.password.focus();
		return false;
	}
	
	if (trim(f1.confirm_password.value)=='')
	{
		alert('Confirm password field cannot be empty');
		f1.confirm_password.focus();
		return false;
	}
	
	if ( trim(f1.confirm_password.value) != trim(f1.password.value) )
	{
		alert('Password and confirm password does not match');
		return false;
	}
	
	if (trim(f1.maker.value)=='')
	{
		alert('Maker field cannot be empty');
		f1.maker.focus();
		return false;
	}
	
	if (trim(f1.model.value)=='')
	{
		alert('Model field cannot be empty');
		f1.model.focus();
		return false;
	}
	
	if (trim(f1.year.value)=='')
	{
		alert('Year field cannot be empty');
		f1.year.focus();
		return false;
	}
	
	/**
	 * Year validation
	 */
	var index = f1.year.options.selectedIndex;
	var state = f1.year.options[index].value;
	
	if (f1.year.value=='0')
	{
		alert('Please, choose a year');
		f1.year.focus();
		return false;
	}
	
	return true;
}