function ValidateInput(form) {
 
 var iChars = "!@#$%^&*()+=-[]\\\';,/{}|\":<>~";

  for (var i = 0; i < document.form.comments.value.length; i++) {
  	if (iChars.indexOf(document.form.comments.value.charAt(i)) != -1) {
  	alert ("The optional comments box has invalid characters. \nThese are not allowed.\n Please remove them and try again.");
  	return false;
  	}
  }
}