// ----------------------------------------------------------------------
// Javascript form validation routines.
// Author: Stephen Poley
//
// Simple routines to quickly pick up obvious typos.
// All validation routines return true if executed by an older browser:
// in this case validation must be left to the server.
//
// Update Jun 2005: discovered that reason IE wasn't setting focus was
// due to an IE timing bug. Added 0.1 sec delay to fix.
//
// Update Oct 2005: minor tidy-up: unused parameter removed
//
// Update Jun 2006: minor improvements to variable names and layout
// ----------------------------------------------------------------------

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

// --------------------------------------------


//                  trim


// Trim leading/trailing whitespace off string


// --------------------------------------------





function trim(str)


{


  return str.replace(/^\s+|\s+$/g, '');


}








// --------------------------------------------


//                  setfocus


// Delayed focus setting to get around IE bug


// --------------------------------------------





function setFocusDelayed()


{


  global_valfield.focus();


}





function setfocus(valfield)


{


  // save valfield in global variable so value retained when routine exits


  global_valfield = valfield;


  setTimeout( 'setFocusDelayed()', 100 );


}








// --------------------------------------------


//                  msg


// Display warn/error message in HTML element.


// commonCheck routine must have previously been called


// --------------------------------------------





function msg(fld,     // id of element to display message in


             msgtype, // class to give element ("warn" or "error")


             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


}





// --------------------------------------------


//            commonCheck


// 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)


// --------------------------------------------





var proceed = 2;  





function commonCheck    (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 != node_text) return true;  // infofield is wrong type of node  





  if (emptyString.test(valfield.value)) {


    if (required) {


      msg (infofield, "error", "ERROR: required");  


      setfocus(valfield);


      return false;


    }


    else {


      msg (infofield, "warn", "");   // OK


      return true;  


    }


  }


  return proceed;


}





// --------------------------------------------


//            validatePresent


// Validate if something has been entered


// Returns true if so 


// --------------------------------------------

function validatePresent(valfield,   // element to be validated
                         infofield ) // id of element to receive info/error msg
{
  var stat = commonCheck (valfield, infofield, true);
  if (stat != proceed) return stat;
  msg (infofield, "warn", "");  
  return true;
}

// --------------------------------------------
//            validateCountry
// Validate if something has been entered
// Returns true if so 
// --------------------------------------------
function validateCountry(valfield,   // element to be validated
                         infofield ) // id of element to receive info/error msg
{
  var stat = commonCheck (valfield, infofield, true);
  if (stat != proceed) return stat;
  msg (infofield, "warn", "");  
  return true;
}

// --------------------------------------------
//               validateEmail
// Validate if e-mail address
// Returns true if so (and also if could not be executed because of old browser)
// --------------------------------------------

function validateEmail  (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
{
  var stat = commonCheck (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  var email = /^[^@]+@[^@.]+\.[^@]*\w\w$/  ;

  if (!email.test(tfld)) {
    msg (infofield, "error", "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)) 
    msg (infofield, "warn", "Unusual e-mail address - check if correct");
  else
    msg (infofield, "warn", "");
  return true;
}

function validateComments(valfield,   // element to be validated
                         infofield ) // id of element to receive info/error msg
{
  var stat = commonCheck (valfield, infofield, true);
  if (stat != proceed) return stat;
  msg (infofield, "warn", "");  
  return true;
}

<!-- Validate Selection -->
function validateAboutUs(valfield,   // element to be validated
                         infofield ) // id of element to receive info/error msg
{
  var stat = commonCheck (valfield, infofield, true);
  if (stat != proceed) return stat;
  msg (infofield, "warn", "");  
  return true;
}