function validate_captcha(key, form_id){
	var word = $('#'+form_id+' #captcha_word').val();
	$.get("captcha_image.php", {key: key, act: "verify", word: word },function(data){
		if(data=='true'){
				$('#'+form_id).submit();
	  }else{
	  	$('#'+form_id+' #captcha_word_error').html('Wrong code!');
			change_captcha(key,form_id); 
	  }			
	});
	return false;
}

function change_captcha(key, form_id){
	$('#'+form_id+' #captcha').attr('src','captcha_image.php?key='+key+'&'+Math.round(Math.random()*100000));
	return false;
}