function check_formular() {
	var f1 = document.forms[0];
	var spr = f1.spr.value;
	if (spr == "de") {
		var wm = "Falsche/Fehlende Eingaben:\n\r\n";
	} else {
		var wm = "wrong/missing entries:\n\r\n";
	}
	var noerror = 1;

	var t1 = f1.name_must;
	if (t1.value == "" || t1.value == " ") {
		if (spr == "de") {
			wm += "Bitte Ihren Namen eingegeben\r\n";
		} else {
			wm += "please enter your name\r\n";
		}
		if (!firsterror) { var firsterror = t1; }
		noerror = 0;
	}

	var t1 = f1.email_must;
	if (t1.value == "" || t1.value == " ") {
		if (spr == "de") {
			wm += "Bitte Ihre email-Adresse eingeben\r\n";
		} else {
			wm += "please enter your email-address\r\n";
		}
		if (!firsterror) { var firsterror = t1; }
		noerror = 0;
	} else if (t1.value.indexOf('@') == -1) {
		if (spr == "de") {
	  	wm += "Die angegebene email-Adresse:\r\n" + t1.value + "\r\nist keine korrekte email-Adresse\r\n";
		} else {
			wm += "the entered email-address:\r\n"+t1.value+"\r\nis no valid email-address\r\n";
		}
		if (!firsterror) { var firsterror = t1; }
  	noerror = 0;
  }

	var t1 = f1.nachricht_must;
	if (t1.value == "" || t1.value == " ") {
		if (spr == "de") {
			wm += "Bitte eine Nachricht eingeben\r\n";
		} else {
			wm += "please enter a message\r\n";
		}
		if (!firsterror) { var firsterror = t1; }
		noerror = 0;
	}

	// --- check if errors occurred ---
	if (noerror == 0) {
		alert(wm);
		firsterror.focus();
		return false;
	}
	else 
		return true;
	
}