function checkEmail(myEmail){
  var ok = true;
  anzAt = 0;
  anzP = 0;
  atP = -1;
  dotP = -1;
  for(i=0;i<myEmail.value.length;i++){
    if(myEmail.value.substring(i,i+1).indexOf("@") == 0){
	  anzAt++;
	  atP = i;
	}
    if(myEmail.value.substring(i,i+1).indexOf(".") == 0){
	  anzP++;
	  dotP = i;
	}
  }
  // position nach dem letzten @
  afterAt = myEmail.value.substring(atP+1,myEmail.value.length);
  // der name nach dem letzten punkt
  topLevelDomain = afterAt.split(".")[afterAt.split(".").length-1];
  //alert(anzAt+"   "+anzP+" dotP="+dotP);
  //dotP = afterAt.indexOf(".");
  if (myEmail.value.length < 8){
    ok = false;
  }else if (atP < 2 || anzAt != 1 || anzP < 1){
    ok = false;
  }else if (dotP <= atP+2){
    ok = false;
  }else if(!checkDomainNames(topLevelDomain,"info,name,museum,aero,coop")){
    ok = false;
  }
  if(ok) return true;
  else return false;
}
function checkDomainNames(theDomain,theOKDomains){
  theOKDomains = theOKDomains.split(",");
  ok = false;
  if(theDomain.length <= 3) ok = true;
  for(i=0;i<theOKDomains.length;i++){
    if (theDomain == theOKDomains[i]) ok = true;
  }
  return ok;
}