// ----------------------------------------------------------------------
// 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).
//
// 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
// ----------------------------------------------------------------------

var nbsp = 160;    // non-breaking space char
var node_text = 3; // DOM text node-type
var emptyString = /^\s*$/
var glb_vfld;      // retain vfld 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()
{
  glb_vfld.focus()
}

function setfocus(vfld)
{
  // save vfld in global variable so value retained when routine exits
  glb_vfld = vfld;
  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.innerHTML = 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    (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.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", "<br>ERROR: Required");
      setfocus(vfld);
      return false;
    }
    else {
      msg (ifld, "warn", "");   // OK
      return true;  
    }
  }
  return proceed;
}

// -----------------------------------------
//            validatePresent
// Validate if something has been entered
// Returns true if so 
// -----------------------------------------

function validatePresent(vfld,   // element to be validated
                         ifld )  // id of element to receive info/error msg
{
  var stat = commonCheck (vfld, ifld, true);
  if (stat != proceed) return stat;

  msg (ifld, "warn", "");  
  return true;
};

function validateDate( vfld, ifld ) {
  var stat = commonCheck (vfld, ifld, true);
  if (stat != proceed) return stat;
  
  var strValue = trim(vfld.value);
  var objRegExp = /^\d{1,2}(\/)\d{1,2}\1\d{4}$/

  //check to see if in correct format
  if(!objRegExp.test(strValue)) {
     msg (ifld, "error", "ERROR: ");
    setfocus(vfld);
    return false; //doesn't match pattern, bad date
  }
  else{
    var strSeparator = strValue.substring(2,3) //find date separator
    var arrayDate = strValue.split(strSeparator); //split date into month, day, year
    //create a lookup for months not equal to Feb.
    var arrayLookup = { '01' : 31,'03' : 31, '04' : 30,'05' : 31,'06' : 30,'07' : 31,
                        '08' : 31,'09' : 30,'10' : 31,'11' : 30,'12' : 31}
    var intDay = parseInt(arrayDate[1]);

    //check if month value and day value agree
    if(arrayLookup[arrayDate[0]] != null) {
      if(intDay <= arrayLookup[arrayDate[0]] && intDay != 0)
        return true; //found in lookup table, good date
    }

    //check for February (bugfix 20050322)
    var intMonth = parseInt(arrayDate[0]);
    if (intMonth == 2) { 
       var intYear = parseInt(arrayDate[2]);
       if( ((intYear % 4 == 0 && intDay <= 29) || (intYear % 4 != 0 && intDay <=28)) && intDay !=0)
          return true; //Feb. had valid number of days
       }
  }
  msg (ifld, "error", "ERROR: ");
  setfocus(vfld);
  return false; //any other values, bad date
}



function validateOnSubmit() {
 var elem;
 var errs=0;
 // execute all element validations in reverse order, so focus gets
 // set to the first one in error.
if (!validatePresent  (document.forms.cart_quantity.txt_3, 'inf_txt_3')) errs += 1; 
if (!validatePresent  (document.forms.cart_quantity.txt_4, 'inf_txt_4')) errs += 1; 
if (!validatePresent  (document.forms.cart_quantity.txt_5, 'inf_txt_5')) errs += 1; 
if (!validatePresent  (document.forms.cart_quantity.txt_6, 'inf_txt_6')) errs += 1; 
 
 if (errs>1)  alert('Some fields have not been completed correctly');
 if (errs==1) alert('There is a field which has not been completed correctly');

 return (errs==0);
};