function echeck(str) {
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1){
		 return false
	}

	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		 return false
	}

	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
			return false
	}

	 if (str.indexOf(at,(lat+1))!=-1){
			return false
	 }

	 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
			return false
	 }

	 if (str.indexOf(dot,(lat+2))==-1){
			return false
	 }
	
	 if (str.indexOf(" ")!=-1){
			return false
	 }

	 return true					
}

function isValidEmail(email) {
   return (email.indexOf(".") > 2) && (email.indexOf("@") > 0);
}

function checkFormGB(form) {
	error = '';
	fields = $(form).getInputs();
	for(i = 0; i < fields.length; i++) {
		required = fields[i].readAttribute('required');
		
		fields[i].style.backgroundColor = '#ffffff';
		if (required == 'true' && fields[i].value == '') {
			fields[i].style.backgroundColor = '#ffc8c8';
			error = $('verplichtveld').value;
		}
		
		if (required == 'email' && !echeck(fields[i].value)) {
			fields[i].style.backgroundColor = '#ffc8c8';
			error = $('emailfout').value;
		}
	}
	
	if (error != '') {
		$('showcheck').innerHTML = '<span class="form_error_tekst">* ' + error + '</span>';
	} else {
		pars = $(form).serialize();		
		pars = pars + '&ajax=gbmail';
		
		url = 'addons/addon.gastenboekmail/sendmail.php';

		new Ajax.Request(url, {method: 'post', parameters: pars, evalScripts: true, onSuccess: function(transport) { $(form).submit(); }});
	}
}