// ----------------------------------------------------------------------
// Routines to validate form field values.
// ----------------------------------------------------------------------

var nbsp = 160;		// non-breaking space char
var DOMNodeTypeText = 3;	// DOM text node-type
var EmptyString = /^\s*$/ ;
var SetFocusDelayedField;	// retain valfield for timer thread


function Trim(str)
//
// Trim leading/trailing whitespace off string
//
{
  return str.replace(/^\s+|\s+$/g, '');
}



//
// Delayed focus setting w/ workaround for IE bug
//
function SetFocusDelayed()
{
  SetFocusDelayedField.focus();
}


function SetFocus(valfield)
{
  // Save valfield in global var
  SetFocusDelayedField = valfield;
  setTimeout( 'SetFocusDelayed()', 100 );
}



//
// Display warn/error message in HTML element.
//

function SetMsg(fld,     // id of element to display message in
             msgtype, // class to give element ("InfoText" or "ErrorText")
             message) // string to display

{
  // setting an empty string can give problems if later set to a 
  // non-empty string, so ensure a space present. (For Mozilla and Opera one could 
  // simply use a space, but IE demands something more, like a non-breaking space.)
  var dispmessage;
  if (EmptyString.test(message)) 
    dispmessage = String.fromCharCode(nbsp);    
  else  
    dispmessage = message;

  var elem = document.getElementById(fld);
  elem.firstChild.nodeValue = dispmessage;  
  
  elem.className = msgtype;   // set the CSS class to adjust appearance of message
}



var proceed = 2;  

// Common code for all validation routines to:
// (a) check for older / less-equipped browsers
// (b) check if empty fields are required
// Returns true (validation passed), 
//         false (validation failed) or 
//         proceed (don't know yet)
function CheckField    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required

{
  if (!document.getElementById) 
    return true;  // not available on this browser - leave validation to the server
  var elem = document.getElementById(infofield);
  if (!elem.firstChild) return true;  // not available on this browser 
  if (elem.firstChild.nodeType != DOMNodeTypeText) return true;  // infofield is wrong type of node  

  if (EmptyString.test(valfield.value)) {
    if (required) {
      SetMsg (infofield, "ErrorText", "(Required)");  
      SetFocus(valfield);
      return false;
    }
    else {
      SetMsg (infofield, "InfoText", "");   // OK
      return true;  
    }
  }
  return proceed;
}


function ValidateText(valfield,   // element to be validated
                         infofield ) // id of element to receive info/error msg
//
// Check that something is entered to the field
// Returns true if so 
//
{
  var stat = CheckField (valfield, infofield, true);
  if (stat != proceed) return stat;

  SetMsg (infofield, "InfoText", "");  
  return true;
}


function ValidateEmail  (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
//
// Validate if e-mail address
// Returns true if so (and also if could not be executed because of old browser)
//
{
  var stat = CheckField (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = Trim(valfield.value);  
  var email = /^[^@]+@[^@.]+\.[^@]*\w\w$/  ;
  if (!email.test(tfld)) {
    SetMsg (infofield, "ErrorText", "ERROR: not a valid e-mail address");
    SetFocus(valfield);
    return false;
  }

  var email2 = /^[A-Za-z][\w.-]+@\w[\w.-]+\.[\w.-]*[A-Za-z][A-Za-z]$/  ;
  if (!email2.test(tfld)) 
    SetMsg (infofield, "InfoText", "Unusual e-mail address - check if correct");
  else
    SetMsg (infofield, "InfoText", "");
  return true;
}