function submitForm(sLang){
	
	//define text
	sErrorDE = 'Bitte ihre eMail-Adresse eingeben.';
	sErrorNL = 'A.u.b.invullen uw E-mail adres.';
	sErrorEN = 'Please enter your eMail-address.';
	
	//switch language
	switch (sLang) {
	  case "de":
		    sError = sErrorDE;
	    break;
	  case "nl":
	    	sError = sErrorNL;
	    break;
	  default:
	    	sError = sErrorEN;
	    break;
	}

	//check fields
	var oEmail = document.getElementById('Email');
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (!filter.test(oEmail.value)) {
		alert(sError);
		oEmail.focus
		return false;
	}
	else
	{
		document.rf.submit();
	}
	
}