if (!Array.prototype.filter)
{
  Array.prototype.filter = function(fun /*, thisp*/)
  {
    var len = this.length;
    if (typeof fun != "function")
      throw new TypeError();

    var res = new Array();
    var thisp = arguments[1];
    for (var i = 0; i < len; i++)
    {
      if (i in this)
      {
        var val = this[i]; // in case fun mutates this
        if (fun.call(thisp, val, i, this))
          res.push(val);
      }
    }

    return res;
  };
}

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


function reviewRadioButtons(thisForm){
 var radio1 = document.getElementById("radio1");
 var radio2 = document.getElementById("radio2");
 var radio3 = document.getElementById("radio3");
var radio3_1 = document.getElementById("radio3_1");
 var radio4 = document.getElementById("radio4");
 var radio5 = document.getElementById("radio5");
 
 var checkbox1 = document.getElementById("checkbox1");
 var searchWord = document.getElementById("term");
 
 id_check = "";
 
 test = function(element, index, array){
    elemend.id != id_check; 
 }
 
 var radioButtons = new Array(radio1, radio2, radio3, radio4, radio5);
 
 if(!radio1.checked){
 	checkbox1.checked = false;	
 }
 
 if(!radio2.checked){
 	radio3.checked = false;
 	radio3_1.checked = false;
    searchWord.bgColor = "gray";
 }
 
 if(radio1.checked){
 	id_check = "radio1";
 	array = radioButtions.filter(test);
 	for(radio in array){
       	radio.checked = false;
    }
 }else if(radio2.checked){
 	id_check = "radio2";
 	array = radioButtions.filter(test);
	
    id_check = "radio3";
 	array = radioButtions.filter(test);
 	for(radio in array){
       	radio.checked = false;
    }
	
 }else if(radio4.checked){
  	id_check = "radio4";
 	array = radioButtions.filter(test);
 	for(radio in array){
       	radio.checked = false;
    }
 }else if(radio5.checked){
  	id_check = "radio5";
 	array = radioButtions.filter(test);
 	for(radio in array){
       	radio.checked = false;
    }
 }

}

function checkDate(month, day){
	var monthSelect = getElementById(month);
	var daySelect = getElementById(day);
	var month = monthhSelect.options[monthSelect.selectedIndex];
	var day = daySelect.options[daySelect.selectedIndex];
	var thirty_months = new Array("April", "June", "September", "November");

	
	if(month == "February"){
		daySelect.remove(30);
		daySelect.remove(31);
	}else if(thirty_months.indexOf(month) != -1){
		if(daySelect.size == 29){
			 try
   			 {
			    daySelect.add(30,null); // standards compliant
		     }
			  catch(ex)
		    {
	            daySelect.add(30); // standards compliant
		    }
  		}else if (daySelect.size == 31){
			daySelect.remove(31);
		}		
	}else{
		if(daySelect.size == 29){
			try
   			 {
			 	daySelect.add(30,null); // standards compliant
			    daySelect.add(31,null); // standards compliant
		     }
			  catch(ex)
		    {
				daySelect.add(30); // standards compliant
	            daySelect.add(31); // standards compliant
		    }
		}else if (daySelect.size == 30){
				try
   			 {
			 	
			    daySelect.add(31,null); // standards compliant
		     }
			  catch(ex)
		    {
				
	            daySelect.add(31); // standards compliant
		    }
		}
	}
	
}

function checkYear(month, day, year){
	var monthSelect = getElementById(month);
	var daySelect = getElementById(day);
	var yearSelect = getElementById(year);
	var month = monthhSelect.options[monthSelect.selectedIndex];
	var day = daySelect.options[daySelect.selectedIndex];
	var year = yearSelect.options[yearSelect.selectedIndex];
	
	var thirty_months = new Array("April", "June", "September", "November");
	//var thirty_one_months = new Array("January", "March", "May", "July", "August", "October", "December");
	
	if(month == "February"){
		if(leapYear(year) && day > 28){
			alert("February only had 28 days in the year " + year + " and your selection has been changed accordingly.");
		}
	}
	
}

function leapYear(year){
	if (inYear % 4 == 0) {
		if (inYear % 100 == 0) {
			return (inYear % 400 == 0);
		} else {
			return true;
		}
	} else {
		return false;
	}
}

function validateForm(x){
	
 var x=document.getElementById("form1");
 for (var i=0;i<x.length;i++)
  {
   document.write(x.elements[i].value);
   document.write("<br />");
  }
	
 return false;
}

// --------------------------------------------
//                  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;
}

// --------------------------------------------
//               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;
}


// --------------------------------------------
//            validateTelnr
// Validate telephone number
// Returns true if so (and also if could not be executed because of old browser)
// Permits spaces, hyphens, brackets and leading +
// --------------------------------------------

function validateTelnr  (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 telnr = /^\+?[0-9 ()-]+[0-9]$/  ;
  if (!telnr.test(tfld)) {
    msg (infofield, "error", "ERROR: not a valid telephone number. Characters permitted are digits, space ()- and leading +");
    setfocus(valfield);
    return false;
  }

  var numdigits = 0;
  for (var j=0; j<tfld.length; j++)
    if (tfld.charAt(j)>='0' && tfld.charAt(j)<='9') numdigits++;

  if (numdigits<6) {
    msg (infofield, "error", "ERROR: " + numdigits + " digits - too short");
    setfocus(valfield);
    return false;
  }

  if (numdigits>14)
    msg (infofield, "warn", numdigits + " digits - check if correct");
  else { 
    if (numdigits<10)
      msg (infofield, "warn", "Only " + numdigits + " digits - check if correct");
    else
      msg (infofield, "warn", "");
  }
  return true;
}

// --------------------------------------------
//             validateAge
// Validate person's age
// Returns true if OK 
// --------------------------------------------

function validateAge    (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);
  var ageRE = /^[0-9]{1,3}$/
  if (!ageRE.test(tfld)) {
    msg (infofield, "error", "ERROR: not a valid age");
    setfocus(valfield);
    return false;
  }

  if (tfld>=200) {
    msg (infofield, "error", "ERROR: not a valid age");
    setfocus(valfield);
    return false;
  }

  if (tfld>110) msg (infofield, "warn", "Older than 110: check correct");
  else {
    if (tfld<7) msg (infofield, "warn", "Bit young for this, aren't you?");
    else        msg (infofield, "warn", "");
  }
  return true;
}