function validate_newsletter_form()
{
	//initialization
	
	var errors = "";
	
	//get form data
	
	var name 				= document.getElementById( "name_tf" ).value;
	
	var email 				= document.getElementById( "email_tf" ).value;
	
	//check form data
	
	//1. name
	
	var empty_text_re 	= new RegExp( "^\\s*$" );
	
	var email_text_re	= new RegExp( "^[^@\\s]+@([-a-zA-Z0-9]+\\.)+[a-zA-Z]{2,}$" );
	
	if ( ( name.length == 0 ) || ( empty_text_re.test( name ) ) )
	{
		errors += "\"Name\" field can not be empty.\n";
	}
		
	if( ( email.length == 0 ) || ( empty_text_re.test( email ) ) )
	{
		errors += "\"E-Mail Address\" field can not be empty.\n";
	}
	else if ( !email_text_re.test( email ) )
	{
		errors += "\"E-Mail Address\" field have invalid format.\n";
	}
	
	if( errors.length > 0 )
	{
		alert( "Form was not filled correctly. Details:\n" + errors );
		
		return false;
	}
	
	//form data are correct
	
	return true;
}

function reset_newsletter_form()
{
	document.getElementById( "name_tf" ).value 	= '';
	
	document.getElementById( "email_tf" ).value = '';
}