intSizeHeader = 100;
//intSizeFooter = 90;
intSizeFooter = 110;

intSizeNavigation = 140;

intLongestNav = 0;

intWidestHeader = 576;
//intWidestHeader = 500;

function ShowStatus(strText) {
	window.status = strText;
}

function SetMainSize(intWidth, intHeight) {
	//alert(intWidth + " " + intHeight);

	//this is where Netscape has issues
	//element = document.all["main"];
	element = document.getElementById("main");

	//alert(intSizeWidth + " " + intSizeHeight);

	element.style.width = intWidth + "px";
	element.style.height = intHeight + "px";
}

function SetNavSize(intWidth, intHeight) {
	//element = document.all["leftnav"];
	element = document.getElementById("leftnav");

	intNavHeight = intHeight - 10;
	
	if (intNavHeight < intLongestNav) {
		element.style.height = intNavHeight + "px";
	} else {
		element.style.height = intLongestNav + "px";	
	}


}

function SetHeaderSize (intWidth, intHeight) {
	//element = document.all["imgheader"];
	element = document.getElementById("imgheader");
	
	intWidth += intSizeNavigation;
	
	if (intWidth > intWidestHeader) {
		element.style.width = intWidestHeader + "px";
	} else {
		element.style.width = intWidth + "px";
	}
}

function SetSizes() {

	intLongestNav = 296;
	//intLongestNav = 350;
	

	intSizeWidth = document.body.clientWidth;
	intSizeHeight = document.body.clientHeight;
		
	intSizeWidth = intSizeWidth - intSizeNavigation;
	intSizeHeight = intSizeHeight - (intSizeHeader + intSizeFooter);
	
	SetMainSize(intSizeWidth, intSizeHeight);

	//alert(intSizeWidth + " " + intSizeHeight);

	SetHeaderSize(intSizeWidth, intSizeHeight);
	SetNavSize(intSizeWidth, intSizeHeight);
}

function LoadPage() {
	//element = document.all["leftnav"];

	//strLongestNav = document.all["leftnav"].style.height;
	//alert(element.style.height);

	SetSizes();
}

function validateForm() {

	if (document.guestbook.message.value == "") {
		alert("You must enter a message to sign the guesbook.")
		document.guestbook.message.focus();
		return false;
	} 
		
	strEmail = document.guestbook.email.value;
	if (strEmail != "") {
		if (emailCheck(strEmail) == false) {
			return false;
		}
	}
	
	return true;
}

function emailCheck (emailStr) {
	//From http://javascript.internet.com/forms/email-address-validation.html

	/* The following variable tells the rest of the function whether or not
	to verify that the address ends in a two-letter country or well-known
	TLD.  1 means check it, 0 means don't. */

	var checkTLD=1;

	/* The following is the list of known TLDs that an e-mail address must end with. */

	var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;

	/* The following pattern is used to check if the entered e-mail address
	fits the user@domain format.  It also is used to separate the username
	from the domain. */

	var emailPat=/^(.+)@(.+)$/;

	/* The following string represents the pattern for matching all special
	characters.  We don't want to allow special characters in the address. 
	These characters include ( ) < > @ , ; : \ " . [ ] */

	var specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]";

	/* The following string represents the range of characters allowed in a 
	username or domainname.  It really states which chars aren't allowed.*/

	var validChars="\[^\\s" + specialChars + "\]";

	/* The following pattern applies if the "user" is a quoted string (in
	which case, there are no rules about which characters are allowed
	and which aren't; anything goes).  E.g. "jiminy cricket"@disney.com
	is a legal e-mail address. */

	var quotedUser="(\"[^\"]*\")";

	/* The following pattern applies for domains that are IP addresses,
	rather than symbolic names.  E.g. joe@[123.124.233.4] is a legal
	e-mail address. NOTE: The square brackets are required. */

	var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;

	/* The following string represents an atom (basically a series of non-special characters.) */

	var atom=validChars + '+';

	/* The following string represents one word in the typical username.
	For example, in john.doe@somewhere.com, john and doe are words.
	Basically, a word is either an atom or quoted string. */

	var word="(" + atom + "|" + quotedUser + ")";

	// The following pattern describes the structure of the user

	var userPat=new RegExp("^" + word + "(\\." + word + ")*$");

	/* The following pattern describes the structure of a normal symbolic
	domain, as opposed to ipDomainPat, shown above. */

	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");

	/* Finally, let's start trying to figure out if the supplied address is valid. */

	/* Begin with the coarse pattern to simply break up user@domain into
	different pieces that are easy to analyze. */

	var matchArray=emailStr.match(emailPat);

	if (matchArray==null) {

	/* Too many/few @'s or something; basically, this address doesn't
	even fit the general mould of a valid e-mail address. */

		alert("Email address seems incorrect (check @ and .'s)");
		document.guestbook.email.focus();
		return false;
	}
	var user=matchArray[1];
	var domain=matchArray[2];

	// Start by checking that only basic ASCII characters are in the strings (0-127).

	for (i=0; i<user.length; i++) {
		if (user.charCodeAt(i)>127) {
			alert("The email's username contains invalid characters.");
			document.guestbook.email.focus();
			return false;
		}
	}
	for (i=0; i<domain.length; i++) {
		if (domain.charCodeAt(i)>127) {
			alert("The email's domain name contains invalid characters.");
			document.guestbook.email.focus();
			return false;
		}
	}

	// See if "user" is valid 

	if (user.match(userPat)==null) {

		// user is not valid

		alert("The email's username doesn't seem to be valid.");
		document.guestbook.email.focus();
		return false;
	}

	/* if the e-mail address is at an IP address (as opposed to a symbolic
	host name) make sure the IP address is valid. */

	var IPArray=domain.match(ipDomainPat);
	if (IPArray!=null) {

		// this is an IP address

		for (var i=1;i<=4;i++) {
			if (IPArray[i]>255) {
				alert("The email's Destination IP address is invalid!");
				document.guestbook.email.focus();
				return false;
			}
		}
		return true;
	}

	// Domain is symbolic name.  Check if it's valid.

	var atomPat=new RegExp("^" + atom + "$");
	var domArr=domain.split(".");
	var len=domArr.length;
	for (i=0;i<len;i++) {
		if (domArr[i].search(atomPat)==-1) {
			alert("The email's domain name does not seem to be valid.");
			document.guestbook.email.focus();
			return false;
		}
	}

	/* domain name seems valid, but now make sure that it ends in a
	known top-level domain (like com, edu, gov) or a two-letter word,
	representing country (uk, nl), and that there's a hostname preceding 
	the domain or country. */

	if (checkTLD && domArr[domArr.length-1].length!=2 && 
	domArr[domArr.length-1].search(knownDomsPat)==-1) {
		alert("The email address must end in a well-known domain or two letter " + "country.");
		document.guestbook.email.focus();
		return false;
	}

	// Make sure there's a host name preceding the domain.

	if (len<2) {
		alert("This email address is missing a hostname!");
		document.guestbook.email.focus();
		return false;
	}

	// If we've gotten this far, everything's valid!
	return true;
}