function popup(url,target)
{
	w = screen.width*(3/4);
	h = screen.height*(3/4);
	l = (screen.width-w)/2;
	t = (screen.height-h)/2;
	widthHeight = "width=640,height=480,left="+l+",top="+t+",menubar=no,resizable=yes,scrollbars=no,status=no,toolbar=no,location=no";
	window.open(url,target,widthHeight);
	return true
}

//Validation
var proceed = 2;  

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

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

function setFocusDelayed(vfld)
{
  glb_vfld.focus()
}

function setfocus(vfld)
{
  glb_vfld = vfld;
  setTimeout( 'setFocusDelayed()', 100 );
}

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
};

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", "required");  
      setfocus(vfld);
      return false;
    }
    else {
      msg (ifld, "warn", "");   // OK
      return true;  
    }
  }
  return proceed;
}


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

 	var tfld = trim(vfld.value);
 	var ageRE = /^[0-9]{1,3}$/

 	if (!ageRE.test(tfld) || (tfld=='')) {
   		msg (ifld, "error", "not a valid age");
   		setfocus(vfld);
   		return false;
	  }

  	if (tfld>=200) {
    		msg (ifld, "error", "not a valid age");
    		setfocus(vfld);
    		return false;
  	}

  	if (tfld>110) {
  		msg (ifld, "warn", "Bit old for this, aren't you?");
  	}
  	else {
    		if (tfld<18) {
    			msg (ifld, "error", "Bit young for this, aren't you?");
    			return false;
    		}
		else {
			msg (ifld, "warn", "");
		}
  	}
  return true;
};