function isEmpty(field){
	field = field.value;
  field = field.replace(/^\s*|\s*$/g,"");
	if (field == "")
		return true;
	else
		return false;
}

function isInvalid(field){
  field = field.value;
  if ((field.indexOf("%") >= 0) || (field.indexOf('"') >= 0) || (field.indexOf("<") >= 0) || (field.indexOf(">") >= 0) || (field.indexOf("'") >= 0) || (field.indexOf("&") >= 0))
    return true;
  else
    return false;
}

function handleInput(field, event, numonly){
  var keyCode = event.keyCode ? event.keyCode : event.which ? event.which : event.charCode;
  var keyChar = String.fromCharCode(keyCode);
  if (keyCode == 13){
    var i;
    for (i = 0; i < field.form.elements.length; i++)
      if (field == field.form.elements[i])
        break;
      i = (i + 1) % field.form.elements.length;
      field.form.elements[i].focus();
      return false;
  } 
  else{
    if (numonly == true){
      if (("0123456789").indexOf(keyChar) > -1)
        return true;
      else
        return false;
    }
    else
      return true;
  }
}