function check() {

  var form = document.forms["formular"];

  for(var i = 0; i < form.elements.length; i++)
    if(form.elements[i].value == "") {
      alert("Keine Eingabe im Feld " + (i+1));
      form.name.focus();
      return false;
    }

  return true;

}

function chkFormular()

{
 if(document.formular.fragen.value == "")  {
   alert("Please insert your remarks!");
   document.formular.fragen.focus();
   return false;
  }

 if(document.formular.name.value == "")  {
   alert("Please insert your name!");
   document.formular.name.focus();
   return false;
  }
 if(!isNaN (document.formular.name.value))  {
   alert ("Only letters are allowed!");
   document.formular.name.focus();
   return false;
  }

 if(document.formular.company.value == "")  {
   alert("Please insert your company!");
   document.formular.company.focus();
   return false;
  }
   if(!isNaN (document.formular.company.value))  {
   alert ("Only letters are allowed!");
   document.formular.company.focus();
   return false;
  }

 if(document.formular.mail.value == "")  {
   alert("Please insert your mail adress!");
   document.formular.mail.focus();
   return false;
  }

  if(document.formular.mail.value.indexOf('@')==-1
    || document.formular.mail.value.indexOf('.')==-1)  {
    alert ("A valid mail adress should contain  \n '@' and '.' \n");
    document.formular.mail.focus();
return false
}

}