// PARAMETER
var constError = "#FFBBBB";
var constOk    = "#ffffff";
var constEmailRegExp = '^[_\.0-9a-zA-Z-]+@([0-9a-zA-Z][0-9a-zA-Z-]+\.)+[a-zA-Z]{2,6}$';
var emailungueltig = "Bitte geben Sie eine gültige E-Mailadresse ein.";

// FORMULAR UND FELDNAMEN
var	Formular = new Array();
Formular["kontakt"] 					= ["nachname", "email", "betreff",  "mitteilung"];

function Check(formularname) {
	
	var IsOk = true;	
	var IsEmailError = false;

	for (feldname in Formular[formularname]) {
		if (document.getElementById(Formular[formularname][feldname]) != null) {
			if (document.getElementById(Formular[formularname][feldname]).value == "") {
				BgFarbe(Formular[formularname][feldname], constError);
				IsOk = false;			
			} else {
				BgFarbe(Formular[formularname][feldname], constOk);
			}
		}
	}

	var emailRule = new RegExp(constEmailRegExp,'gi'); 

	if (document.getElementById("email") != null) {
		if (document.getElementById("email").value != "") {
			if (!emailRule.test(document.getElementById("email").value)) {
				BgFarbe("email", constError);
				IsEmailError = true;
			} else {
				BgFarbe("email", constOk);
			}
		} else {
  		BgFarbe("email", constError);
			IsOk = false;
		}
	}

  if (IsEmailError) {
		alert(emailungueltig);
	} 

  if (IsOk && !IsEmailError)
		return true;
	else {
		return false;
	}
}

function BgFarbe(feldname, farbe) {
	document.getElementById(feldname).style.backgroundColor = farbe;
}