// ----------------------------------------------------------------------
// 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 Aug 2004: have tested that IE 5.0 and IE 5.5 both support DOM model
// sufficiently well, so innerHTML option removed (redundant).
// ----------------------------------------------------------------------

var nbsp = 160;    // non-breaking space char
var node_text = 3; // DOM text node-type
var emptyString = /^\s*$/

// -----------------------------------------
//                  trim
// Trim leading/trailing whitespace off string
// -----------------------------------------

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

// -----------------------------------------
//                  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  
    elem.firstChild.nodeValue = elem.firstChild.nodeValue +'<br>'+dispmessage; 

  var elem = document.getElementById(fld); 
  try{
  	elem.className = msgtype;
  }catch(err){
	alert(" could not find element "+fld);  
  }
};

// -----------------------------------------
//            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    (vfld,   // element to be validated
                         ifld,   // id of element to receive info/error msg
                         reqd)   // true if required
{
  if (!document.getElementById) 
    return true;  // not available on this browser - leave validation to the server
  var elem = document.getElementById(ifld);
  /*
  if(elem){
		if (!elem.firstChild)
    		return true;  // not available on this browser 
  		if (elem.firstChild.nodeType != node_text)
    		return true;  // ifld is wrong type of node  
  }
  */
  if (emptyString.test(vfld.value)) {
    if (reqd) {
      msg (ifld, "error", "");  
      vfld.focus();
      return false;
    }
    else {
      msg (ifld, "norm", "");   // OK
      return true;  
    }
  }
  msg (ifld, "norm", "");   // OK
  return proceed;
}