function isDelimiter(c) {
  return " ,;.:!?()-".indexOf(c) >= 0;
}

function validateInquiry(text) {
var len = text.length;
var j = 0;
while (j < len) { // find a significant character
while ((j < len) && isDelimiter(text.charAt(j))) { j++; }
// question with non-empty string?
if (j < len)
return true;
}
alert('Eine Frage, bitte!');
return false;
}