function isValid() {
	var error_message = "Input error:\n";
  var checked = false;
  var name = document.query_form.name.value;
  var re_email = /^([_a-zA-Z0-9-]+)(\.[_a-zA-Z0-9-]+)*@([a-zA-Z0-9-]+\.)+([a-zA-Z]{2,3})$/;
  var email = document.query_form.email.value;
  var subject = document.query_form.subject.value;
  var querytext = document.query_form.querytext.value;
  var kapsch = document.query_form.secutext.value;
  var result = document.query_form.securesult.value;
  
	if (name == "") {
		checked = true;
		error_message += "- Please type in your name!\n";
		document.query_form.name.style.border = "1px solid red";
	}

  if ((re_email.test(email))==false || email.length==0) {
  	error_message += "- Please type in your email address correctly!\n";
  	document.query_form.email.style.border = "1px solid red";
  	checked = true;
  }
  if (subject == 0) {
  	error_message += "- Please choose one of the departments!\n";
  	document.query_form.subject.style.border = "1px solid red";
  	checked = true;
  }
  if (querytext == "") {
  	error_message += "- Please fill out the textbox!\n"
  	document.query_form.querytext.style.border = "1px solid red";
  	checked = true;
  }

  if (kapsch !== "k?mNb") {
  	checked = true;
  	error_message += "- Please type in the same text as seen in the picture!\n";
  	document.query_form.secutext.style.border = "1px solid red";
  }
  
  if (result !== "36") {
  	checked = true;
  	error_message += "- Please type in the correct result of the arithmetic problem!\n";
  	document.query_form.securesult.style.border = "1px solid red";
  }

  if (checked) {
  	error_message += "\nPlease fill out the form correctly!";
  	alert(error_message);
  	return false;
  } else {
  	return true;  	
  }
  return checked;
}

function changeBorder1 (Feld) {
  if (Feld !== "") {
    document.query_form.name.style.border = "1px solid grey";
  }
}

function changeBorder2 (Feld) {
  if (Feld !== "") {
    document.query_form.name.style.border = "1px solid grey";
  }
}

function changeBorder3 (Feld) {
  if (Feld !== "") {
    document.query_form.name.style.border = "1px solid grey";
  }
}

function changeBorder4 (Feld) {
  if (Feld !== "") {
    document.query_form.name.style.border = "1px solid grey";
  }
}

function resizeDiv(query_form) {
	document.getElementById (query_form).style.visibility = 'visible';
	document.getElementById (query_form).style.display = 'block';
	document.getElementById (query_form).style.height = '270px';
	document.getElementById (query_form).style.width = '100%';
}